サーバー証明書を取得します。
[root@server1 ~]# certbot certonly –standalone -d メールサーバー名
↑ メールサーバー上にWebサーバーが稼動していない場合です。
Postfix(OpenSSL・Let’s Encrypt・Certbot)
暗号化に対応した設定をします。
[root@server1 ~]# dnf -y install postfix ← Postfixをインストールします。
[root@server1 ~]# vi /etc/postfix/main.cf ← Postfixの設定ファイルを編集します。
# Global Postfix configuration file. This file lists only a subset
# of all parameters. For the syntax, and for a complete parameter
# list, see the postconf(5) manual page (command: "man 5 postconf").
#
# For common configuration examples, see BASIC_CONFIGURATION_README
# and STANDARD_CONFIGURATION_README. To find these documents, use
# the command "postconf html_directory readme_directory", or go to
# http://www.postfix.org/BASIC_CONFIGURATION_README.html etc.
#
# For best results, change no more than 2-3 parameters at a time,
# and test if Postfix still works after every change.
# COMPATIBILITY
#
# The compatibility_level determines what default settings Postfix
# will use for main.cf and master.cf settings. These defaults will
# change over time.
#
# To avoid breaking things, Postfix will use backwards-compatible
# default settings and log where it uses those old backwards-compatible
# default settings, until the system administrator has determined
# if any backwards-compatible default settings need to be made
# permanent in main.cf or master.cf.
#
# When this review is complete, update the compatibility_level setting
# below as recommended in the RELEASE_NOTES file.
#
# The level below is what should be used with new (not upgrade) installs.
#
compatibility_level = 2
# SOFT BOUNCE
#
# The soft_bounce parameter provides a limited safety net for
# testing. When soft_bounce is enabled, mail will remain queued that
# would otherwise bounce. This parameter disables locally-generated
# bounces, and prevents the SMTP server from rejecting mail permanently
# (by changing 5xx replies into 4xx replies). However, soft_bounce
# is no cure for address rewriting mistakes or mail routing mistakes.
#
#soft_bounce = no
# LOCAL PATHNAME INFORMATION
#
# The queue_directory specifies the location of the Postfix queue.
# This is also the root directory of Postfix daemons that run chrooted.
# See the files in examples/chroot-setup for setting up Postfix chroot
# environments on different UNIX systems.
#
queue_directory = /var/spool/postfix
# The command_directory parameter specifies the location of all
# postXXX commands.
#
command_directory = /usr/sbin
# The daemon_directory parameter specifies the location of all Postfix
# daemon programs (i.e. programs listed in the master.cf file). This
# directory must be owned by root.
#
daemon_directory = /usr/libexec/postfix
# The data_directory parameter specifies the location of Postfix-writable
# data files (caches, random numbers). This directory must be owned
# by the mail_owner account (see below).
#
data_directory = /var/lib/postfix
# QUEUE AND PROCESS OWNERSHIP
#
# The mail_owner parameter specifies the owner of the Postfix queue
# and of most Postfix daemon processes. Specify the name of a user
# account THAT DOES NOT SHARE ITS USER OR GROUP ID WITH OTHER ACCOUNTS
# AND THAT OWNS NO OTHER FILES OR PROCESSES ON THE SYSTEM. In
# particular, don't specify nobody or daemon. PLEASE USE A DEDICATED
# USER.
#
mail_owner = postfix
# The default_privs parameter specifies the default rights used by
# the local delivery agent for delivery to external file or command.
# These rights are used in the absence of a recipient user context.
# DO NOT SPECIFY A PRIVILEGED USER OR THE POSTFIX OWNER.
#
#default_privs = nobody
# INTERNET HOST AND DOMAIN NAMES
#
# The myhostname parameter specifies the internet hostname of this
# mail system. The default is to use the fully-qualified domain name
# from gethostname(). $myhostname is used as a default value for many
# other configuration parameters.
#
#myhostname = host.domain.tld
myhostname = server1.zoah.net ← 追加(メールサーバー名を指定します。)
# The mydomain parameter specifies the local internet domain name.
# The default is to use $myhostname minus the first component.
# $mydomain is used as a default value for many other configuration
# parameters.
#
mydomain = zoah.net ← 追加(自ドメイン名を指定します。)
# SENDING MAIL
#
# The myorigin parameter specifies the domain that locally-posted
# mail appears to come from. The default is to append $myhostname,
# which is fine for small sites. If you run a domain with multiple
# machines, you should (1) change this to $mydomain and (2) set up
# a domain-wide alias database that aliases each user to
# user@that.users.mailhost.
#
# For the sake of consistency between sender and recipient addresses,
# myorigin also specifies the default domain name that is appended
# to recipient addresses that have no @domain part.
#
#myorigin = $myhostname
myorigin = $mydomain ← 追加(ローカルからのメール送信時の送信元メールアドレス@以降にドメイン名を付加します。)
# RECEIVING MAIL
# The inet_interfaces parameter specifies the network interface
# addresses that this mail system receives mail on. By default,
# the software claims all active interfaces on the machine. The
# parameter also controls delivery of mail to user@[ip.address].
#
# See also the proxy_interfaces parameter, for network addresses that
# are forwarded to us via a proxy or network address translator.
#
# Note: you need to stop/start Postfix when this parameter changes.
#
#inet_interfaces = all
#inet_interfaces = $myhostname
#inet_interfaces = $myhostname, localhost
↓
inet_interfaces = all ← 変更します。(外部からのメール受信を許可します。)
# Enable IPv4, and IPv6 if supported
#inet_protocols = all
inet_protocols = ipv4
# The proxy_interfaces parameter specifies the network interface
# addresses that this mail system receives mail on by way of a
# proxy or network address translation unit. This setting extends
# the address list specified with the inet_interfaces parameter.
#
# You must specify your proxy/NAT addresses when your system is a
# backup MX host for other domains, otherwise mail delivery loops
# will happen when the primary MX host is down.
#
#proxy_interfaces =
#proxy_interfaces = 1.2.3.4
# The mydestination parameter specifies the list of domains that this
# machine considers itself the final destination for.
#
# These domains are routed to the delivery agent specified with the
# local_transport parameter setting. By default, that is the UNIX
# compatible delivery agent that lookups all recipients in /etc/passwd
# and /etc/aliases or their equivalent.
#
# The default is $myhostname + localhost.$mydomain + localhost. On
# a mail domain gateway, you should also include $mydomain.
#
# Do not specify the names of virtual domains - those domains are
# specified elsewhere (see VIRTUAL_README).
#
# Do not specify the names of domains that this machine is backup MX
# host for. Specify those names via the relay_domains settings for
# the SMTP server, or use permit_mx_backup if you are lazy (see
# STANDARD_CONFIGURATION_README).
#
# The local machine is always the final destination for mail addressed
# to user@[the.net.work.address] of an interface that the mail system
# receives mail on (see the inet_interfaces parameter).
#
# Specify a list of host or domain names, /file/name or type:table
# patterns, separated by commas and/or whitespace. A /file/name
# pattern is replaced by its contents; a type:table is matched when
# a name matches a lookup key (the right-hand side is ignored).
# Continue long lines by starting the next line with whitespace.
#
# See also below, section "REJECTING MAIL FOR UNKNOWN LOCAL USERS".
#
mydestination = $myhostname, localhost.$mydomain, localhost, $mydomain ← 変更(自ドメイン宛メールを受信できるようにします。)
#mydestination = $myhostname, localhost.$mydomain, localhost, $mydomain
#mydestination = $myhostname, localhost.$mydomain, localhost, $mydomain,
# mail.$mydomain, www.$mydomain, ftp.$mydomain
# REJECTING MAIL FOR UNKNOWN LOCAL USERS
#
# The local_recipient_maps parameter specifies optional lookup tables
# with all names or addresses of users that are local with respect
# to $mydestination, $inet_interfaces or $proxy_interfaces.
#
# If this parameter is defined, then the SMTP server will reject
# mail for unknown local users. This parameter is defined by default.
#
# To turn off local recipient checking in the SMTP server, specify
# local_recipient_maps = (i.e. empty).
#
# The default setting assumes that you use the default Postfix local
# delivery agent for local delivery. You need to update the
# local_recipient_maps setting if:
#
# - You define $mydestination domain recipients in files other than
# /etc/passwd, /etc/aliases, or the $virtual_alias_maps files.
# For example, you define $mydestination domain recipients in
# the $virtual_mailbox_maps files.
#
# - You redefine the local delivery agent in master.cf.
#
# - You redefine the "local_transport" setting in main.cf.
#
# - You use the "luser_relay", "mailbox_transport", or "fallback_transport"
# feature of the Postfix local delivery agent (see local(8)).
#
# Details are described in the LOCAL_RECIPIENT_README file.
#
# Beware: if the Postfix SMTP server runs chrooted, you probably have
# to access the passwd file via the proxymap service, in order to
# overcome chroot restrictions. The alternative, having a copy of
# the system passwd file in the chroot jail is just not practical.
#
# The right-hand side of the lookup tables is conveniently ignored.
# In the left-hand side, specify a bare username, an @domain.tld
# wild-card, or specify a user@domain.tld address.
#
#local_recipient_maps = unix:passwd.byname $alias_maps
#local_recipient_maps = proxy:unix:passwd.byname $alias_maps
#local_recipient_maps =
# The unknown_local_recipient_reject_code specifies the SMTP server
# response code when a recipient domain matches $mydestination or
# ${proxy,inet}_interfaces, while $local_recipient_maps is non-empty
# and the recipient address or address local-part is not found.
#
# The default setting is 550 (reject mail) but it is safer to start
# with 450 (try again later) until you are certain that your
# local_recipient_maps settings are OK.
#
unknown_local_recipient_reject_code = 550
# TRUST AND RELAY CONTROL
# The mynetworks parameter specifies the list of "trusted" SMTP
# clients that have more privileges than "strangers".
#
# In particular, "trusted" SMTP clients are allowed to relay mail
# through Postfix. See the smtpd_recipient_restrictions parameter
# in postconf(5).
#
# You can specify the list of "trusted" network addresses by hand
# or you can let Postfix do it for you (which is the default).
#
# By default (mynetworks_style = subnet), Postfix "trusts" SMTP
# clients in the same IP subnetworks as the local machine.
# On Linux, this works correctly only with interfaces specified
# with the "ifconfig" command.
#
# Specify "mynetworks_style = class" when Postfix should "trust" SMTP
# clients in the same IP class A/B/C networks as the local machine.
# Don't do this with a dialup site - it would cause Postfix to "trust"
# your entire provider's network. Instead, specify an explicit
# mynetworks list by hand, as described below.
#
# Specify "mynetworks_style = host" when Postfix should "trust"
# only the local machine.
#
#mynetworks_style = class
#mynetworks_style = subnet
#mynetworks_style = host
# Alternatively, you can specify the mynetworks list by hand, in
# which case Postfix ignores the mynetworks_style setting.
#
# Specify an explicit list of network/netmask patterns, where the
# mask specifies the number of bits in the network part of a host
# address.
#
# You can also specify the absolute pathname of a pattern file instead
# of listing the patterns here. Specify type:table for table-based lookups
# (the value on the table right-hand side is not used).
#
#mynetworks = 168.100.189.0/28, 127.0.0.0/8
#mynetworks = $config_directory/mynetworks
#mynetworks = hash:/etc/postfix/network_table
mynetworks = 127.0.0.0/8,192.168.100.0/24
# The relay_domains parameter restricts what destinations this system will
# relay mail to. See the smtpd_recipient_restrictions description in
# postconf(5) for detailed information.
#
# By default, Postfix relays mail
# - from "trusted" clients (IP address matches $mynetworks) to any destination,
# - from "untrusted" clients to destinations that match $relay_domains or
# subdomains thereof, except addresses with sender-specified routing.
# The default relay_domains value is $mydestination.
#
# In addition to the above, the Postfix SMTP server by default accepts mail
# that Postfix is final destination for:
# - destinations that match $inet_interfaces or $proxy_interfaces,
# - destinations that match $mydestination
# - destinations that match $virtual_alias_domains,
# - destinations that match $virtual_mailbox_domains.
# These destinations do not need to be listed in $relay_domains.
#
# Specify a list of hosts or domains, /file/name patterns or type:name
# lookup tables, separated by commas and/or whitespace. Continue
# long lines by starting the next line with whitespace. A file name
# is replaced by its contents; a type:name table is matched when a
# (parent) domain appears as lookup key.
#
# NOTE: Postfix will not automatically forward mail for domains that
# list this system as their primary or backup MX host. See the
# permit_mx_backup restriction description in postconf(5).
#
relay_domains = $mydestination
# INTERNET OR INTRANET
# The relayhost parameter specifies the default host to send mail to
# when no entry is matched in the optional transport(5) table. When
# no relayhost is given, mail is routed directly to the destination.
#
# On an intranet, specify the organizational domain name. If your
# internal DNS uses no MX records, specify the name of the intranet
# gateway host instead.
#
# In the case of SMTP, specify a domain, host, host:port, [host]:port,
# [address] or [address]:port; the form [host] turns off MX lookups.
#
# If you're connected via UUCP, see also the default_transport parameter.
#
#relayhost = $mydomain
#relayhost = [gateway.my.domain]
#relayhost = [mailserver.isp.tld]
#relayhost = uucphost
#relayhost = [an.ip.add.ress]
# REJECTING UNKNOWN RELAY USERS
#
# The relay_recipient_maps parameter specifies optional lookup tables
# with all addresses in the domains that match $relay_domains.
#
# If this parameter is defined, then the SMTP server will reject
# mail for unknown relay users. This feature is off by default.
#
# The right-hand side of the lookup tables is conveniently ignored.
# In the left-hand side, specify an @domain.tld wild-card, or specify
# a user@domain.tld address.
#
#relay_recipient_maps = hash:/etc/postfix/relay_recipients
# INPUT RATE CONTROL
#
# The in_flow_delay configuration parameter implements mail input
# flow control. This feature is turned on by default, although it
# still needs further development (it's disabled on SCO UNIX due
# to an SCO bug).
#
# A Postfix process will pause for $in_flow_delay seconds before
# accepting a new message, when the message arrival rate exceeds the
# message delivery rate. With the default 100 SMTP server process
# limit, this limits the mail inflow to 100 messages a second more
# than the number of messages delivered per second.
#
# Specify 0 to disable the feature. Valid delays are 0..10.
#
#in_flow_delay = 1s
# ADDRESS REWRITING
#
# The ADDRESS_REWRITING_README document gives information about
# address masquerading or other forms of address rewriting including
# username->Firstname.Lastname mapping.
# ADDRESS REDIRECTION (VIRTUAL DOMAIN)
#
# The VIRTUAL_README document gives information about the many forms
# of domain hosting that Postfix supports.
# "USER HAS MOVED" BOUNCE MESSAGES
#
# See the discussion in the ADDRESS_REWRITING_README document.
# TRANSPORT MAP
#
# See the discussion in the ADDRESS_REWRITING_README document.
# ALIAS DATABASE
#
# The alias_maps parameter specifies the list of alias databases used
# by the local delivery agent. The default list is system dependent.
#
# On systems with NIS, the default is to search the local alias
# database, then the NIS alias database. See aliases(5) for syntax
# details.
#
# If you change the alias database, run "postalias /etc/aliases" (or
# wherever your system stores the mail alias file), or simply run
# "newaliases" to build the necessary DBM or DB file.
#
# It will take a minute or so before changes become visible. Use
# "postfix reload" to eliminate the delay.
#
#alias_maps = dbm:/etc/aliases
alias_maps = hash:/etc/aliases
#alias_maps = hash:/etc/aliases, nis:mail.aliases
#alias_maps = netinfo:/aliases
# The alias_database parameter specifies the alias database(s) that
# are built with "newaliases" or "sendmail -bi". This is a separate
# configuration parameter, because alias_maps (see above) may specify
# tables that are not necessarily all under control by Postfix.
#
#alias_database = dbm:/etc/aliases
#alias_database = dbm:/etc/mail/aliases
alias_database = hash:/etc/aliases
#alias_database = hash:/etc/aliases, hash:/opt/majordomo/aliases
# ADDRESS EXTENSIONS (e.g., user+foo)
#
# The recipient_delimiter parameter specifies the separator between
# user names and address extensions (user+foo). See canonical(5),
# local(8), relocated(5) and virtual(5) for the effects this has on
# aliases, canonical, virtual, relocated and .forward file lookups.
# Basically, the software tries user+foo and .forward+foo before
# trying user and .forward.
#
#recipient_delimiter = +
# DELIVERY TO MAILBOX
#
# The home_mailbox parameter specifies the optional pathname of a
# mailbox file relative to a user's home directory. The default
# mailbox file is /var/spool/mail/user or /var/mail/user. Specify
# "Maildir/" for qmail-style delivery (the / is required).
#
#home_mailbox = Mailbox
home_mailbox = Maildir/ ← 追加(メール格納形式をMaildir形式にします。)
# The mail_spool_directory parameter specifies the directory where
# UNIX-style mailboxes are kept. The default setting depends on the
# system type.
#
#mail_spool_directory = /var/mail
#mail_spool_directory = /var/spool/mail
# The mailbox_command parameter specifies the optional external
# command to use instead of mailbox delivery. The command is run as
# the recipient with proper HOME, SHELL and LOGNAME environment settings.
# Exception: delivery for root is done as $default_user.
#
# Other environment variables of interest: USER (recipient username),
# EXTENSION (address extension), DOMAIN (domain part of address),
# and LOCAL (the address localpart).
#
# Unlike other Postfix configuration parameters, the mailbox_command
# parameter is not subjected to $parameter substitutions. This is to
# make it easier to specify shell syntax (see example below).
#
# Avoid shell meta characters because they will force Postfix to run
# an expensive shell process. Procmail alone is expensive enough.
#
# IF YOU USE THIS TO DELIVER MAIL SYSTEM-WIDE, YOU MUST SET UP AN
# ALIAS THAT FORWARDS MAIL FOR ROOT TO A REAL USER.
#
#mailbox_command = /some/where/procmail
#mailbox_command = /some/where/procmail -a "$EXTENSION"
mailbox_command = /usr/bin/procmail
# The mailbox_transport specifies the optional transport in master.cf
# to use after processing aliases and .forward files. This parameter
# has precedence over the mailbox_command, fallback_transport and
# luser_relay parameters.
#
# Specify a string of the form transport:nexthop, where transport is
# the name of a mail delivery transport defined in master.cf. The
# :nexthop part is optional. For more details see the sample transport
# configuration file.
#
# NOTE: if you use this feature for accounts not in the UNIX password
# file, then you must update the "local_recipient_maps" setting in
# the main.cf file, otherwise the SMTP server will reject mail for
# non-UNIX accounts with "User unknown in local recipient table".
#
# Cyrus IMAP over LMTP. Specify ``lmtpunix cmd="lmtpd"
# listen="/var/imap/socket/lmtp" prefork=0'' in cyrus.conf.
#mailbox_transport = lmtp:unix:/var/lib/imap/socket/lmtp
# If using the cyrus-imapd IMAP server deliver local mail to the IMAP
# server using LMTP (Local Mail Transport Protocol), this is prefered
# over the older cyrus deliver program by setting the
# mailbox_transport as below:
#
# mailbox_transport = lmtp:unix:/var/lib/imap/socket/lmtp
#
# The efficiency of LMTP delivery for cyrus-imapd can be enhanced via
# these settings.
#
# local_destination_recipient_limit = 300
# local_destination_concurrency_limit = 5
#
# Of course you should adjust these settings as appropriate for the
# capacity of the hardware you are using. The recipient limit setting
# can be used to take advantage of the single instance message store
# capability of Cyrus. The concurrency limit can be used to control
# how many simultaneous LMTP sessions will be permitted to the Cyrus
# message store.
#
# Cyrus IMAP via command line. Uncomment the "cyrus...pipe" and
# subsequent line in master.cf.
#mailbox_transport = cyrus
# The fallback_transport specifies the optional transport in master.cf
# to use for recipients that are not found in the UNIX passwd database.
# This parameter has precedence over the luser_relay parameter.
#
# Specify a string of the form transport:nexthop, where transport is
# the name of a mail delivery transport defined in master.cf. The
# :nexthop part is optional. For more details see the sample transport
# configuration file.
#
# NOTE: if you use this feature for accounts not in the UNIX password
# file, then you must update the "local_recipient_maps" setting in
# the main.cf file, otherwise the SMTP server will reject mail for
# non-UNIX accounts with "User unknown in local recipient table".
#
#fallback_transport = lmtp:unix:/var/lib/imap/socket/lmtp
#fallback_transport =
# The luser_relay parameter specifies an optional destination address
# for unknown recipients. By default, mail for unknown@$mydestination,
# unknown@[$inet_interfaces] or unknown@[$proxy_interfaces] is returned
# as undeliverable.
#
# The following expansions are done on luser_relay: $user (recipient
# username), $shell (recipient shell), $home (recipient home directory),
# $recipient (full recipient address), $extension (recipient address
# extension), $domain (recipient domain), $local (entire recipient
# localpart), $recipient_delimiter. Specify ${name?value} or
# ${name:value} to expand value only when $name does (does not) exist.
#
# luser_relay works only for the default Postfix local delivery agent.
#
# NOTE: if you use this feature for accounts not in the UNIX password
# file, then you must specify "local_recipient_maps =" (i.e. empty) in
# the main.cf file, otherwise the SMTP server will reject mail for
# non-UNIX accounts with "User unknown in local recipient table".
#
#luser_relay = $user@other.host
#luser_relay = $local@other.host
#luser_relay = admin+$local
# JUNK MAIL CONTROLS
#
# The controls listed here are only a very small subset. The file
# SMTPD_ACCESS_README provides an overview.
# The header_checks parameter specifies an optional table with patterns
# that each logical message header is matched against, including
# headers that span multiple physical lines.
#
# By default, these patterns also apply to MIME headers and to the
# headers of attached messages. With older Postfix versions, MIME and
# attached message headers were treated as body text.
#
# For details, see "man header_checks".
#
#header_checks = regexp:/etc/postfix/header_checks
# FAST ETRN SERVICE
#
# Postfix maintains per-destination logfiles with information about
# deferred mail, so that mail can be flushed quickly with the SMTP
# "ETRN domain.tld" command, or by executing "sendmail -qRdomain.tld".
# See the ETRN_README document for a detailed description.
#
# The fast_flush_domains parameter controls what destinations are
# eligible for this service. By default, they are all domains that
# this server is willing to relay mail to.
#
#fast_flush_domains = $relay_domains
# SHOW SOFTWARE VERSION OR NOT
#
# The smtpd_banner parameter specifies the text that follows the 220
# code in the SMTP server's greeting banner. Some people like to see
# the mail version advertised. By default, Postfix shows no version.
#
# You MUST specify $myhostname at the start of the text. That is an
# RFC requirement. Postfix itself does not care.
#
#smtpd_banner = $myhostname ESMTP $mail_name
#smtpd_banner = $myhostname ESMTP $mail_name ($mail_version)
smtpd_banner = $myhostname ESMTP unknown ← 追加(メールサーバーソフト名を隠蔽します。)
# PARALLEL DELIVERY TO THE SAME DESTINATION
#
# How many parallel deliveries to the same user or domain? With local
# delivery, it does not make sense to do massively parallel delivery
# to the same user, because mailbox updates must happen sequentially,
# and expensive pipelines in .forward files can cause disasters when
# too many are run at the same time. With SMTP deliveries, 10
# simultaneous connections to the same domain could be sufficient to
# raise eyebrows.
#
# Each message delivery transport has its XXX_destination_concurrency_limit
# parameter. The default is $default_destination_concurrency_limit for
# most delivery transports. For the local delivery agent the default is 2.
#local_destination_concurrency_limit = 2
#default_destination_concurrency_limit = 20
# DEBUGGING CONTROL
#
# The debug_peer_level parameter specifies the increment in verbose
# logging level when an SMTP client or server host name or address
# matches a pattern in the debug_peer_list parameter.
#
debug_peer_level = 2
# The debug_peer_list parameter specifies an optional list of domain
# or network patterns, /file/name patterns or type:name tables. When
# an SMTP client or server host name or address matches a pattern,
# increase the verbose logging level by the amount specified in the
# debug_peer_level parameter.
#
#debug_peer_list = 127.0.0.1
#debug_peer_list = some.domain
# The debugger_command specifies the external command that is executed
# when a Postfix daemon program is run with the -D option.
#
# Use "command .. & sleep 5" so that the debugger can attach before
# the process marches on. If you use an X-based debugger, be sure to
# set up your XAUTHORITY environment variable before starting Postfix.
#
debugger_command =
PATH=/bin:/usr/bin:/usr/local/bin:/usr/X11R6/bin
ddd $daemon_directory/$process_name $process_id & sleep 5
# If you can't use X, use this to capture the call stack when a
# daemon crashes. The result is in a file in the configuration
# directory, and is named after the process name and the process ID.
#
# debugger_command =
# PATH=/bin:/usr/bin:/usr/local/bin; export PATH; (echo cont;
# echo where) | gdb $daemon_directory/$process_name $process_id 2>&1
# >$config_directory/$process_name.$process_id.log & sleep 5
#
# Another possibility is to run gdb under a detached screen session.
# To attach to the screen session, su root and run "screen -r
# <id_string>" where <id_string> uniquely matches one of the detached
# sessions (from "screen -list").
#
# debugger_command =
# PATH=/bin:/usr/bin:/sbin:/usr/sbin; export PATH; screen
# -dmS $process_name gdb $daemon_directory/$process_name
# $process_id & sleep 1
# INSTALL-TIME CONFIGURATION INFORMATION
#
# The following parameters are used when installing a new Postfix version.
#
# sendmail_path: The full pathname of the Postfix sendmail command.
# This is the Sendmail-compatible mail posting interface.
#
sendmail_path = /usr/sbin/sendmail.postfix
# newaliases_path: The full pathname of the Postfix newaliases command.
# This is the Sendmail-compatible command to build alias databases.
#
newaliases_path = /usr/bin/newaliases.postfix
# mailq_path: The full pathname of the Postfix mailq command. This
# is the Sendmail-compatible mail queue listing command.
#
mailq_path = /usr/bin/mailq.postfix
# setgid_group: The group for mail submission and queue management
# commands. This must be a group name with a numerical group ID that
# is not shared with other accounts, not even with the Postfix account.
#
setgid_group = postdrop
# html_directory: The location of the Postfix HTML documentation.
#
html_directory = no
# manpage_directory: The location of the Postfix on-line manual pages.
#
manpage_directory = /usr/share/man
# sample_directory: The location of the Postfix sample configuration files.
# This parameter is obsolete as of Postfix 2.1.
#
sample_directory = /usr/share/doc/postfix/samples
# readme_directory: The location of the Postfix README files.
#
readme_directory = /usr/share/doc/postfix/README_FILES
# TLS CONFIGURATION
#
# Basic Postfix TLS configuration by default with self-signed certificate
# for inbound SMTP and also opportunistic TLS for outbound SMTP.
# The full pathname of a file with the Postfix SMTP server RSA certificate
# in PEM format. Intermediate certificates should be included in general,
# the server certificate first, then the issuing CA(s) (bottom-up order).
#
smtpd_tls_cert_file = /etc/letsencrypt/live/server1.zoah.net-0003/fullchain.pem ← サーバー証明書と中間証明書を指定します。
# The full pathname of a file with the Postfix SMTP server RSA private key
# in PEM format. The private key must be accessible without a pass-phrase,
# i.e. it must not be encrypted.
#
smtpd_tls_key_file = /etc/letsencrypt/live/server1.zoah.net-0003/privkey.pem ← 秘密鍵を指定します。
# Announce STARTTLS support to remote SMTP clients, but do not require that
# clients use TLS encryption (opportunistic TLS inbound).
#
smtpd_tls_security_level = may ← このように編集します。
# Directory with PEM format Certification Authority certificates that the
# Postfix SMTP client uses to verify a remote SMTP server certificate.
#
#smtp_tls_CApath = /etc/pki/tls/certs
# The full pathname of a file containing CA certificates of root CAs
# trusted to sign either remote SMTP server certificates or intermediate CA
# certificates.
#
#smtp_tls_CAfile = /etc/pki/tls/certs/ca-bundle.crt
# Use TLS if this is supported by the remote SMTP server, otherwise use
# plaintext (opportunistic TLS outbound).
#
smtp_tls_security_level = may ← このように編集します。
meta_directory = /etc/postfix
shlib_directory = /usr/lib64/postfix
smtpd_sasl_auth_enable = yes ← 追加(SMTP認証設定)
以下を追加して下さい。
---ここから---
policy-spf_time_limit = 3600s
smtpd_recipient_restrictions = permit_mynetworks, permit_sasl_authenticated, check_relay_domains, reject_rbl_client, reject zen.spamhaus.org, check_policy_service unix:private/policyd-spf
#smtpd_relay_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination, smtpd_recipient_restrictions, reject_rbl_client, reject zen.spamhaus.org, check_policy_service unix:private/policyd-spf
---ここまで---
以下を追加して下さい。
---ここから---
smtpd_client_restrictions =
reject_rbl_client zen.spamhaus.org
# check_client_access hash:/etc/postfix/access
# reject_non_fqdn_sender
# reject_unknown_sender_domain
---ここまで---
message_size_limit = 409600000 ← 追加(例:送受信メールサイズを約400MBにする場合※デフォルト:10240000)
mailbox_size_limit = 2048000000 ← 1つのメールボックスの最大容量です。デフォルトは50MB(51200000)です。 ※ mailbox_size_limit の値のほうが message_size_limit の値より大きくなるようにして下さい。そうしないと、エラーになります。
masquerade_domains = zoah.net
local_recipient_maps =
luser_relay = unknown_user@localhost
↓ 下記を追加します。
smtpd_tls_session_cache_database = btree:/var/lib/postfix/smtpd_scache
↓ 下記を追加します。※使用する暗号化方法を指定します。(脆弱性のある暗号化方法を除外します。)
---ここから---
tls_high_cipherlist = kEECDH:+kEECDH+SHA:kEDH:+kEDH+SHA:+kEDH+CAMELLIA:kECDH:+kECDH+SHA:kRSA:+kRSA+SHA:+kRSA+CAMELLIA:!aNULL:!eNULL:!SSLv2:!RC4:!MD5:!DES:!EXP:!SEED:!IDEA:!3DES
smtp_tls_ciphers = high
smtpd_tls_ciphers = high
smtpd_tls_mandatory_ciphers = high
---ここまで---
↓ 下記を追加します。※脆弱性のある暗号化方式（SSLv2,SSLv3）を無効化します。
---ここから---
smtpd_tls_mandatory_protocols=!SSLv2,!SSLv3
smtp_tls_mandatory_protocols=!SSLv2,!SSLv3
smtpd_tls_protocols=!SSLv2,!SSLv3
smtp_tls_protocols=!SSLv2,!SSLv3
---ここまで---
milter_default_action = accept
milter_protocol = 6
#smtpd_milters = unix:/run/spamass-milter/postfix/sock
#non_smtpd_milters = unix:/run/spamass-milter/postfix/sock
#smtpd_milters = inet:127.0.0.1:8891,inet:127.0.0.1:8893,unix:/var/run/clamav-milter/clamav-milter.socket,unix:/run/spamass-milter/postfix/sock
smtpd_milters = inet:localhost:8891,inet:localhost:8893,unix:/var/run/clamav-milter/clamav-milter.socket,unix:/run/spamass-milter/postfix/sock
non_smtpd_milters = $smtpd_milters,unix:/var/run/clamav-milter/clamav-milter.socket,unix:/run/spamass-milter/postfix/sock
smtpd_sasl_security_options = noanonymous ← このように編集します。
broken_sasl_auth_clients = yes ← このように編集します。
smtpd_sasl_local_domain = $mydomain ← このように編集します。
smtp_sasl_mechanism_filter = plain,login ← このように編集します。
#VERY IMPORTANT
smtpd_sasl_tls_security_options = noanonymous ← このように編集します。
smtpd_tls_received_header = yes ← このように編集します。
#smtp_sasl_password_maps = hash:/etc/postfix/smtp_password
smtp_sasl_tls_security_options = noanonymous ← このように編集します。
smtpd_helo_required = yes ← このように編集します。
disable_vrfy_command = yes ← このように編集します。
[root@server1 ~]# vi /etc/postfix/master.cf ← postfixの設定ファイル(master.cf)を編集します。
#
# Postfix master process configuration file. For details on the format
# of the file, see the master(5) manual page (command: "man 5 master" or
# on-line: http://www.postfix.org/master.5.html).
#
# Do not forget to execute "postfix reload" after editing this file.
#
# ==========================================================================
# service type private unpriv chroot wakeup maxproc command + args
# (yes) (yes) (no) (never) (100)
# ==========================================================================
smtp inet n - n - - smtpd -o smtpd_sasl_auth_enable=yes
-o milter_macro_daemon_name=VERIFYING
smtp inet n - n - 1 postscreen
smtpd pass - - n - - smtpd
#dnsblog unix - - n - 0 dnsblog
#tlsproxy unix - - n - 0 tlsproxy
submission inet n - n - - smtpd ← 行頭の#を削除してコメントを解除します。(SUBMISSIONポートを有効化します。)
-o syslog_name=postfix/submission
-o smtpd_tls_security_level=may ← このように編集します。
# -o smtpd_sasl_auth_enable=yes
# -o smtpd_tls_auth_only=yes
# -o smtpd_reject_unlisted_recipient=no
# -o smtpd_client_restrictions=$mua_client_restrictions
# -o smtpd_helo_restrictions=$mua_helo_restrictions
# -o smtpd_sender_restrictions=$mua_sender_restrictions
# -o smtpd_recipient_restrictions=
# -o smtpd_relay_restrictions=permit_sasl_authenticated,reject
# -o milter_macro_daemon_name=ORIGINATING
smtps inet n - n - - smtpd ← 行頭の#を削除してコメントを解除します。(SMTPSを有効化します。)
# -o syslog_name=postfix/smtps
-o smtpd_tls_wrappermode=yes ← 行頭の#を削除してコメント解除(SMTPS有効化)
-o smtpd_sasl_auth_enable=yes ← 行頭の#を削除してコメントを解除します。(SUBMISSIONポートでSMTP認証を有効化します。)
# -o smtpd_reject_unlisted_recipient=no
# -o smtpd_client_restrictions=$mua_client_restrictions
# -o smtpd_helo_restrictions=$mua_helo_restrictions
# -o smtpd_sender_restrictions=$mua_sender_restrictions
# -o smtpd_recipient_restrictions=
# -o smtpd_relay_restrictions=permit_sasl_authenticated,reject
# -o milter_macro_daemon_name=ORIGINATING
#628 inet n - n - - qmqpd
pickup unix n - n 60 1 pickup
cleanup unix n - n - 0 cleanup
qmgr unix n - n 300 1 qmgr
#qmgr unix n - n 300 1 oqmgr
tlsmgr unix - - n 1000? 1 tlsmgr
rewrite unix - - n - - trivial-rewrite
bounce unix - - n - 0 bounce
defer unix - - n - 0 bounce
trace unix - - n - 0 bounce
verify unix - - n - 1 verify
flush unix n - n 1000? 0 flush
proxymap unix - - n - - proxymap
proxywrite unix - - n - 1 proxymap
smtp unix - - n - - smtp
relay unix - - n - - smtp
-o syslog_name=postfix/$service_name
# -o smtp_helo_timeout=5 -o smtp_connect_timeout=5
showq unix n - n - - showq
error unix - - n - - error
retry unix - - n - - error
discard unix - - n - - discard
local unix - n n - - local
virtual unix - n n - - virtual
lmtp unix - - n - - lmtp
anvil unix - - n - 1 anvil
scache unix - - n - 1 scache
postlog unix-dgram n - n - 1 postlogd
#
# ====================================================================
# Interfaces to non-Postfix software. Be sure to examine the manual
# pages of the non-Postfix software to find out what options it wants.
#
# Many of the following services use the Postfix pipe(8) delivery
# agent. See the pipe(8) man page for information about ${recipient}
# and other message envelope options.
# ====================================================================
#
# maildrop. See the Postfix MAILDROP_README file for details.
# Also specify in main.cf: maildrop_destination_recipient_limit=1
#
#maildrop unix - n n - - pipe
# flags=DRXhu user=vmail argv=/usr/local/bin/maildrop -d ${recipient}
#
# ====================================================================
#
# Recent Cyrus versions can use the existing "lmtp" master.cf entry.
#
# Specify in cyrus.conf:
# lmtp cmd="lmtpd -a" listen="localhost:lmtp" proto=tcp4
#
# Specify in main.cf one or more of the following:
# mailbox_transport = lmtp:inet:localhost
# virtual_transport = lmtp:inet:localhost
#
# ====================================================================
#
# Cyrus 2.1.5 (Amos Gouaux)
# Also specify in main.cf: cyrus_destination_recipient_limit=1
#
#cyrus unix - n n - - pipe
# flags=DRX user=cyrus argv=/usr/lib/cyrus-imapd/deliver -e -r ${sender} -m ${extension} ${user}
#
# ====================================================================
#
# Old example of delivery via Cyrus.
#
#old-cyrus unix - n n - - pipe
# flags=R user=cyrus argv=/usr/lib/cyrus-imapd/deliver -e -m ${extension} ${user}
#
# ====================================================================
#
# See the Postfix UUCP_README file for configuration details.
#
#uucp unix - n n - - pipe
# flags=Fqhu user=uucp argv=uux -r -n -z -a$sender - $nexthop!rmail ($recipient)
#
# ====================================================================
#
# Other external delivery methods.
#
#ifmail unix - n n - - pipe
# flags=F user=ftn argv=/usr/lib/ifmail/ifmail -r $nexthop ($recipient)
#
#bsmtp unix - n n - - pipe
# flags=Fq. user=bsmtp argv=/usr/local/sbin/bsmtp -f $sender $nexthop $recipient
#
#scalemail-backend unix - n n - 2 pipe
# flags=R user=scalemail argv=/usr/lib/scalemail/bin/scalemail-store
# ${nexthop} ${user} ${extension}
#
#mailman unix - n n - - pipe
# flags=FRX user=list argv=/usr/lib/mailman/bin/postfix-to-mailman.py
# ${nexthop} ${user}
-o smtp_data_done_timeout=1200
-o smtp_send_xforward_command=yes
-o disable_dns_lookups=yes
#127.0.0.1:10025 inet n - n - - smtpd
-o content_filter=
-o local_recipient_maps=
-o relay_recipient_maps=
-o smtpd_restriction_classes=
-o smtpd_client_restrictions=permit_sasl_authenticated,reject
-o smtpd_helo_restrictions=
-o smtpd_sender_restrictions=
# -o smtpd_recipient_restrictions=reject_non_fqdn_recipient,reject_unknown_recipient_domain,permit_sasl_authenticated,reject
-o smtpd_recipient_restrictions=permit_sasl_authenticated,reject
-o mynetworks=127.0.0.0/8,192.168.100.0/24
-o strict_rfc821_envelopes=yes
-o smtpd_error_sleep_time=0
-o smtpd_soft_error_limit=1001
-o smtpd_hard_error_limit=1000
policyd-spf unix - n n - 0 spawn
argv=/usr/bin/python3 /usr/bin/policyd-spf /etc/python-policyd-spf/policyd-spf.conf
[root@server1 ~]# systemctl restart postfix ← Postfixを再起動します。
[root@server1 ~]# systemctl enable postfix ← Postfixを自動的に起動するように設定します。
Dovecot
[root@server1 ~]# dnf -y install dovecot ← Dovecotをインストールします。
[root@server1 ~]# vi /etc/dovecot/conf.d/10-mail.conf ← 10-mail.confを編集します。
##
## Mailbox locations and namespaces
##
# Location for users' mailboxes. The default is empty, which means that Dovecot
# tries to find the mailboxes automatically. This won't work if the user
# doesn't yet have any mail, so you should explicitly tell Dovecot the full
# location.
#
# If you're using mbox, giving a path to the INBOX file (eg. /var/mail/%u)
# isn't enough. You'll also need to tell Dovecot where the other mailboxes are
# kept. This is called the "root mail directory", and it must be the first
# path given in the mail_location setting.
#
# There are a few special variables you can use, eg.:
#
# %u - username
# %n - user part in user@domain, same as %u if there's no domain
# %d - domain part in user@domain, empty if there's no domain
# %h - home directory
#
# See doc/wiki/Variables.txt for full list. Some examples:
#
# mail_location = maildir:~/Maildir
# mail_location = mbox:~/mail:INBOX=/var/mail/%u
# mail_location = mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%n
#
# <doc/wiki/MailLocation.txt>
#
#mail_location =
mail_location = maildir:~/Maildir ← 追加(メール格納形式をMaildir形式にします。)
# If you need to set multiple mailbox locations or want to change default
# namespace settings, you can do it by defining namespace sections.
#
# You can have private, shared and public namespaces. Private namespaces
# are for user's personal mails. Shared namespaces are for accessing other
# users' mailboxes that have been shared. Public namespaces are for shared
# mailboxes that are managed by sysadmin. If you create any shared or public
# namespaces you'll typically want to enable ACL plugin also, otherwise all
# users can access all the shared mailboxes, assuming they have permissions
# on filesystem level to do so.
namespace inbox {
# Namespace type: private, shared or public
#type = private
# Hierarchy separator to use. You should use the same separator for all
# namespaces or some clients get confused. '/' is usually a good one.
# The default however depends on the underlying mail storage format.
#separator =
# Prefix required to access this namespace. This needs to be different for
# all namespaces. For example "Public/".
#prefix =
# Physical location of the mailbox. This is in same format as
# mail_location, which is also the default for it.
#location =
# There can be only one INBOX, and this setting defines which namespace
# has it.
inbox = yes
# If namespace is hidden, it's not advertised to clients via NAMESPACE
# extension. You'll most likely also want to set list=no. This is mostly
# useful when converting from another server with different namespaces which
# you want to deprecate but still keep working. For example you can create
# hidden namespaces with prefixes "~/mail/", "~%u/mail/" and "mail/".
#hidden = no
# Show the mailboxes under this namespace with LIST command. This makes the
# namespace visible for clients that don't support NAMESPACE extension.
# "children" value lists child mailboxes, but hides the namespace prefix.
#list = yes
# Namespace handles its own subscriptions. If set to "no", the parent
# namespace handles them (empty prefix should always have this as "yes")
#subscriptions = yes
# See 15-mailboxes.conf for definitions of special mailboxes.
}
# Example shared namespace configuration
#namespace {
#type = shared
#separator = /
# Mailboxes are visible under "shared/user@domain/"
# %%n, %%d and %%u are expanded to the destination user.
#prefix = shared/%%u/
# Mail location for other users' mailboxes. Note that %variables and ~/
# expands to the logged in user's data. %%n, %%d, %%u and %%h expand to the
# destination user's data.
#location = maildir:%%h/Maildir:INDEX=~/Maildir/shared/%%u
# Use the default namespace for saving subscriptions.
#subscriptions = no
# List the shared/ namespace only if there are visible shared mailboxes.
#list = children
#}
# Should shared INBOX be visible as "shared/user" or "shared/user/INBOX"?
#mail_shared_explicit_inbox = no
# System user and group used to access mails. If you use multiple, userdb
# can override these by returning uid or gid fields. You can use either numbers
# or names. <doc/wiki/UserIds.txt>
#mail_uid =
#mail_gid =
# Group to enable temporarily for privileged operations. Currently this is
# used only with INBOX when either its initial creation or dotlocking fails.
# Typically this is set to "mail" to give access to /var/mail.
#mail_privileged_group =
# Grant access to these supplementary groups for mail processes. Typically
# these are used to set up access to shared mailboxes. Note that it may be
# dangerous to set these if users can create symlinks (e.g. if "mail" group is
# set here, ln -s /var/mail ~/mail/var could allow a user to delete others'
# mailboxes, or ln -s /secret/shared/box ~/mail/mybox would allow reading it).
#mail_access_groups =
# Allow full filesystem access to clients. There's no access checks other than
# what the operating system does for the active UID/GID. It works with both
# maildir and mboxes, allowing you to prefix mailboxes names with eg. /path/
# or ~user/.
#mail_full_filesystem_access = no
# Dictionary for key=value mailbox attributes. This is used for example by
# URLAUTH and METADATA extensions.
#mail_attribute_dict =
# A comment or note that is associated with the server. This value is
# accessible for authenticated users through the IMAP METADATA server
# entry "/shared/comment".
#mail_server_comment = ""
# Indicates a method for contacting the server administrator. According to
# RFC 5464, this value MUST be a URI (e.g., a mailto: or tel: URL), but that
# is currently not enforced. Use for example mailto:admin@example.com. This
# value is accessible for authenticated users through the IMAP METADATA server
# entry "/shared/admin".
#mail_server_admin =
##
## Mail processes
##
# Don't use mmap() at all. This is required if you store indexes to shared
# filesystems (NFS or clustered filesystem).
#mmap_disable = no
# Rely on O_EXCL to work when creating dotlock files. NFS supports O_EXCL
# since version 3, so this should be safe to use nowadays by default.
#dotlock_use_excl = yes
# When to use fsync() or fdatasync() calls:
# optimized (default): Whenever necessary to avoid losing important data
# always: Useful with e.g. NFS when write()s are delayed
# never: Never use it (best performance, but crashes can lose data)
#mail_fsync = optimized
# Locking method for index files. Alternatives are fcntl, flock and dotlock.
# Dotlocking uses some tricks which may create more disk I/O than other locking
# methods. NFS users: flock doesn't work, remember to change mmap_disable.
#lock_method = fcntl
# Directory where mails can be temporarily stored. Usually it's used only for
# mails larger than >= 128 kB. It's used by various parts of Dovecot, for
# example LDA/LMTP while delivering large mails or zlib plugin for keeping
# uncompressed mails.
#mail_temp_dir = /tmp
# Valid UID range for users, defaults to 500 and above. This is mostly
# to make sure that users can't log in as daemons or other system users.
# Note that denying root logins is hardcoded to dovecot binary and can't
# be done even if first_valid_uid is set to 0.
first_valid_uid = 500 ← ログイン可能なUIDを500以上に変更します。
#last_valid_uid = 0
# Valid GID range for users, defaults to non-root/wheel. Users having
# non-valid GID as primary group ID aren't allowed to log in. If user
# belongs to supplementary groups with non-valid GIDs, those groups are
# not set.
#first_valid_gid = 1
#last_valid_gid = 0
# Maximum allowed length for mail keyword name. It's only forced when trying
# to create new keywords.
#mail_max_keyword_length = 50
# ':' separated list of directories under which chrooting is allowed for mail
# processes (ie. /var/mail will allow chrooting to /var/mail/foo/bar too).
# This setting doesn't affect login_chroot, mail_chroot or auth chroot
# settings. If this setting is empty, "/./" in home dirs are ignored.
# WARNING: Never add directories here which local users can modify, that
# may lead to root exploit. Usually this should be done only if you don't
# allow shell access for users. <doc/wiki/Chrooting.txt>
#valid_chroot_dirs =
# Default chroot directory for mail processes. This can be overridden for
# specific users in user database by giving /./ in user's home directory
# (eg. /home/./user chroots into /home). Note that usually there is no real
# need to do chrooting, Dovecot doesn't allow users to access files outside
# their mail directory anyway. If your home directories are prefixed with
# the chroot directory, append "/." to mail_chroot. <doc/wiki/Chrooting.txt>
#mail_chroot =
# UNIX socket path to master authentication server to find users.
# This is used by imap (for shared users) and lda.
#auth_socket_path = /var/run/dovecot/auth-userdb
# Directory where to look up mail plugins.
#mail_plugin_dir = /usr/lib/dovecot
# Space separated list of plugins to load for all services. Plugins specific to
# IMAP, LDA, etc. are added to this list in their own .conf files.
#mail_plugins =
##
## Mailbox handling optimizations
##
# Mailbox list indexes can be used to optimize IMAP STATUS commands. They are
# also required for IMAP NOTIFY extension to be enabled.
#mailbox_list_index = yes
# Trust mailbox list index to be up-to-date. This reduces disk I/O at the cost
# of potentially returning out-of-date results after e.g. server crashes.
# The results will be automatically fixed once the folders are opened.
#mailbox_list_index_very_dirty_syncs = yes
# Should INBOX be kept up-to-date in the mailbox list index? By default it's
# not, because most of the mailbox accesses will open INBOX anyway.
#mailbox_list_index_include_inbox = no
# The minimum number of mails in a mailbox before updates are done to cache
# file. This allows optimizing Dovecot's behavior to do less disk writes at
# the cost of more disk reads.
#mail_cache_min_mail_count = 0
# When IDLE command is running, mailbox is checked once in a while to see if
# there are any new mails or other changes. This setting defines the minimum
# time to wait between those checks. Dovecot can also use inotify and
# kqueue to find out immediately when changes occur.
#mailbox_idle_check_interval = 30 secs
# Save mails with CR+LF instead of plain LF. This makes sending those mails
# take less CPU, especially with sendfile() syscall with Linux and FreeBSD.
# But it also creates a bit more disk I/O which may just make it slower.
# Also note that if other software reads the mboxes/maildirs, they may handle
# the extra CRs wrong and cause problems.
#mail_save_crlf = no
# Max number of mails to keep open and prefetch to memory. This only works with
# some mailbox formats and/or operating systems.
#mail_prefetch_count = 0
# How often to scan for stale temporary files and delete them (0 = never).
# These should exist only after Dovecot dies in the middle of saving mails.
#mail_temp_scan_interval = 1w
# How many slow mail accesses sorting can perform before it returns failure.
# With IMAP the reply is: NO [LIMIT] Requested sort would have taken too long.
# The untagged SORT reply is still returned, but it's likely not correct.
#mail_sort_max_read_count = 0
protocol !indexer-worker {
# If folder vsize calculation requires opening more than this many mails from
# disk (i.e. mail sizes aren't in cache already), return failure and finish
# the calculation via indexer process. Disabled by default. This setting must
# be 0 for indexer-worker processes.
#mail_vsize_bg_after_count = 0
}
##
## Maildir-specific settings
##
# By default LIST command returns all entries in maildir beginning with a dot.
# Enabling this option makes Dovecot return only entries which are directories.
# This is done by stat()ing each entry, so it causes more disk I/O.
# (For systems setting struct dirent->d_type, this check is free and it's
# done always regardless of this setting)
#maildir_stat_dirs = no
# When copying a message, do it with hard links whenever possible. This makes
# the performance much better, and it's unlikely to have any side effects.
#maildir_copy_with_hardlinks = yes
# Assume Dovecot is the only MUA accessing Maildir: Scan cur/ directory only
# when its mtime changes unexpectedly or when we can't find the mail otherwise.
#maildir_very_dirty_syncs = no
# If enabled, Dovecot doesn't use the S=<size> in the Maildir filenames for
# getting the mail's physical size, except when recalculating Maildir++ quota.
# This can be useful in systems where a lot of the Maildir filenames have a
# broken size. The performance hit for enabling this is very small.
#maildir_broken_filename_sizes = no
# Always move mails from new/ directory to cur/, even when the \Recent flags
# aren't being reset.
#maildir_empty_new = no
##
## mbox-specific settings
##
# Which locking methods to use for locking mbox. There are four available:
# dotlock: Create <mailbox>.lock file. This is the oldest and most NFS-safe
# solution. If you want to use /var/mail/ like directory, the users
# will need write access to that directory.
# dotlock_try: Same as dotlock, but if it fails because of permissions or
# because there isn't enough disk space, just skip it.
# fcntl : Use this if possible. Works with NFS too if lockd is used.
# flock : May not exist in all systems. Doesn't work with NFS.
# lockf : May not exist in all systems. Doesn't work with NFS.
#
# You can use multiple locking methods; if you do the order they're declared
# in is important to avoid deadlocks if other MTAs/MUAs are using multiple
# locking methods as well. Some operating systems don't allow using some of
# them simultaneously.
#mbox_read_locks = fcntl
#mbox_write_locks = dotlock fcntl
mbox_write_locks = fcntl
# Maximum time to wait for lock (all of them) before aborting.
#mbox_lock_timeout = 5 mins
# If dotlock exists but the mailbox isn't modified in any way, override the
# lock file after this much time.
#mbox_dotlock_change_timeout = 2 mins
# When mbox changes unexpectedly we have to fully read it to find out what
# changed. If the mbox is large this can take a long time. Since the change
# is usually just a newly appended mail, it'd be faster to simply read the
# new mails. If this setting is enabled, Dovecot does this but still safely
# fallbacks to re-reading the whole mbox file whenever something in mbox isn't
# how it's expected to be. The only real downside to this setting is that if
# some other MUA changes message flags, Dovecot doesn't notice it immediately.
# Note that a full sync is done with SELECT, EXAMINE, EXPUNGE and CHECK
# commands.
#mbox_dirty_syncs = yes
# Like mbox_dirty_syncs, but don't do full syncs even with SELECT, EXAMINE,
# EXPUNGE or CHECK commands. If this is set, mbox_dirty_syncs is ignored.
#mbox_very_dirty_syncs = no
# Delay writing mbox headers until doing a full write sync (EXPUNGE and CHECK
# commands and when closing the mailbox). This is especially useful for POP3
# where clients often delete all mails. The downside is that our changes
# aren't immediately visible to other MUAs.
#mbox_lazy_writes = yes
# If mbox size is smaller than this (e.g. 100k), don't write index files.
# If an index file already exists it's still read, just not updated.
#mbox_min_index_size = 0
# Mail header selection algorithm to use for MD5 POP3 UIDLs when
# pop3_uidl_format=%m. For backwards compatibility we use apop3d inspired
# algorithm, but it fails if the first Received: header isn't unique in all
# mails. An alternative algorithm is "all" that selects all headers.
#mbox_md5 = apop3d
##
## mdbox-specific settings
##
# Maximum dbox file size until it's rotated.
#mdbox_rotate_size = 10M
# Maximum dbox file age until it's rotated. Typically in days. Day begins
# from midnight, so 1d = today, 2d = yesterday, etc. 0 = check disabled.
#mdbox_rotate_interval = 0
# When creating new mdbox files, immediately preallocate their size to
# mdbox_rotate_size. This setting currently works only in Linux with some
# filesystems (ext4, xfs).
#mdbox_preallocate_space = no
##
## Mail attachments
##
# sdbox and mdbox support saving mail attachments to external files, which
# also allows single instance storage for them. Other backends don't support
# this for now.
# Directory root where to store mail attachments. Disabled, if empty.
#mail_attachment_dir =
# Attachments smaller than this aren't saved externally. It's also possible to
# write a plugin to disable saving specific attachments externally.
#mail_attachment_min_size = 128k
# Filesystem backend to use for saving attachments:
# posix : No SiS done by Dovecot (but this might help FS's own deduplication)
# sis posix : SiS with immediate byte-by-byte comparison during saving
# sis-queue posix : SiS with delayed comparison and deduplication
#mail_attachment_fs = sis posix
# Hash format to use in attachment filenames. You can add any text and
# variables: %{md4}, %{md5}, %{sha1}, %{sha256}, %{sha512}, %{size}.
# Variables can be truncated, e.g. %{sha256:80} returns only first 80 bits
#mail_attachment_hash = %{sha1}
# Settings to control adding $HasAttachment or $HasNoAttachment keywords.
# By default, all MIME parts with Content-Disposition=attachment, or inlines
# with filename parameter are consired attachments.
# add-flags - Add the keywords when saving new mails or when fetching can
# do it efficiently.
# content-type=type or !type - Include/exclude content type. Excluding will
# never consider the matched MIME part as attachment. Including will only
# negate an exclusion (e.g. content-type=!foo/* content-type=foo/bar).
# exclude-inlined - Exclude any Content-Disposition=inline MIME part.
#mail_attachment_detection_options =
disable_plaintext_auth = no
[root@server1 ~]# vi /etc/dovecot/conf.d/10-auth.conf ← 10-auth.confを編集します。
# Disable LOGIN command and all other plaintext authentications unless # SSL/TLS is used (LOGINDISABLED capability). Note that if the remote IP # matches the local IP (ie. you're connecting from the same computer), the # connection is considered secure and plaintext authentication is allowed. # See also ssl=required setting. #disable_plaintext_auth = yes disable_plaintext_auth = no ← 追加(プレインテキスト認証を許可します。)
[root@server1 ~]# vi /etc/dovecot/conf.d/10-ssl.conf ← Dovecotの設定ファイルを編集します。
# PEM encoded X.509 SSL/TLS certificate and private key. They're opened before # dropping root privileges, so keep the key file unreadable by anyone but # root. Included doc/mkcert.sh can be used to easily generate self-signed # certificate, just make sure to update the domains in dovecot-openssl.cnf ssl_cert = </etc/letsencrypt/live/server1.zoah.net-0003/fullchain.pem ← サーバー証明書と中間証明書を指定します。 ssl_key = </etc/letsencrypt/live/server1.zoah.net-0003/privkey.pem ← 秘密鍵を指定します。
[root@server1 ~]# systemctl start dovecot ← Dovecotを起動します。
[root@server1 ~]# systemctl enable dovecot ← Dovecotを自動的に起動するように設定します。
SPF・DKIM・DMARC の設定方法
SPF
[root@server1 ~]# dnf config-manager –set-enabled crb
[root@server1 ~]# dnf install epel-release
[root@server1 ~]# dnf update
[root@server1 ~]# dnf install pypolicyd-spf ← pypolicyd-spf をインストールします。
[root@server1 ~]# vi /etc/python-policyd-spf/policyd-spf.conf
HELO_reject = Fail ↓ HELO_reject = False ← 受信したメールのヘッダにSPFの検証結果を追加するのみとして、メールを破棄しないように設定します。 Mail_From_reject = Fail ↓ Mail_From_reject = False ← 受信したメールのヘッダにSPFの検証結果を追加するのみとして、メールを破棄しないように設定します。
[root@server1 ~]# vi /etc/postfix/master.cf
下記を最終行に追加します。
policyd-spf unix - n n - 0 spawn user=nobody argv=/usr/libexec/postfix/policyd-spf
[root@server1 ~]# vi /etc/postfix/main.cf
policy-spf_time_limit = 3600s ← pypolicyd-spf のタイムアウトの設定を追加します。(単位は秒です) smtpd_recipient_restrictions = permit_mynetworks, permit_sasl_authenticated, check_relay_domains, reject_rbl_client, reject zen.spamhaus.org, check_policy_service unix:private/policyd-spf ← 左のように編集します。※ check_policy_service unix:private/policyd-spf は、必ず一番最後に追加して下さい。先頭に追加するとオープンリレーになります。
DNS設定のゾーン情報に以下のようなレコードを登録します。
IN TXT "v=spf1 a:server1.zoah.net mx ~all" ↑ server1.zoah.netは、各自のメールサーバー名に置き換えて下さい。
DKIM
[root@server1 ~]# dnf install opendkim ← OpenDKIMをインストールします。
[root@server1 ~]# dnf install opendkim-tools ← ツールをインストールします。
[root@server1 ~]# mkdir /etc/opendkim/keys/zoah.net ← 鍵ファイルの作成先ディレクトリを作ります。ディレクトリをドメイン名にしておくと、複数のドメインを管理する時に便利です。
↓ opendkim-genkey コマンドで鍵ファイル(秘密鍵と公開鍵)を作成します。
[root@server1 ~]# opendkim-genkey -v -b 2048 -D /etc/opendkim/keys/zoah.net -d zoah.net -s default
【オプションの説明】
-v 実行結果を表示します。
-b 鍵の長さを指定します。デフォルト値は 1024ビットですが、2048ビットが推奨されることが多いです。
-D 鍵ファイルの作成先ディレクトリを指定します。
-d ドメイン名を指定
-s セレクタ名(セレクタ名はこの後の設定でよく使いますので、覚えやすいものを設定しましょう。)
↓ 鍵ファイルのオーナーを opendkim に変更します。
[root@server1 ~]# chown opendkim:opendkim /etc/opendkim/keys/t.apar.jp/default.private
[root@server1 ~]# chown opendkim:opendkim /etc/opendkim/keys/t.apar.jp/default.txt
以上で下記２つの鍵ファイル(秘密鍵と公開鍵)が作成されました。ここで作成した公開鍵をDNSサーバーに登録します。一方の秘密鍵は、秘密にして漏洩などしないように厳重に管理して下さい。
/etc/opendkim/keys/zoah.net/default.private ←秘密鍵
/etc/opendkim/keys/zoah.net/default.txt ←公開鍵
DNSサーバーに登録する為の公開鍵レコードと、ADSPレコードを作成します。
公開鍵レコードの書式
＜セレクタ名＞._domainkey.＜ドメイン名＞. IN TXT “v=DKIM1; k=rsa; p=＜公開鍵のデータ＞”
「p=」の後に指定する＜公開鍵のデータ＞は、公開鍵ファイルの下記斜体文字の部分です。
[root@server1 ~]# cat /etc/opendkim/keys/zoah.net/default.txt
—ここから—
default._domainkey IN TXT ( “v=DKIM1; k=rsa; “
“p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAhPjDVIuuuF5TGVCW/U1+TKGj3khf8i8rZlTlgTDrvqcRQKLJERwWeagxzS4sbUcU/9WVPRGeUbQQ+IJdwgQ9Ia5g7h1rjcybpyNgp2iNSXfOz/l/K5tbRR0kLIapmY8Grp9Kt4D8Z7R/3X2ftGs1VQL+B72ZGIy9ZhzuSPSI/0DHjvaI2V4qfudsnmbnF54tbEL0L67zy63Osk”
“N0cNifqJziwuXyaKKezFsb5KIPoW2dagAs/KNdbleptahmGbG22KL+WJQEP2gUdaX9sTyeKWrwJhi1M8TujLcvX77zIBusHzv14ku296k4gUptYQfF5n/hzjJ35vHCA7lseqHnTQIDAQAB” ) ; —– DKIM key default for zoah.net
—ここまで—
一般的なDNSサーバのTXTレコードの最大文字数は255文字のため、鍵の長さが2048ビットの場合、公開鍵のデータが255文字を超えてしまいます。その為、そのままでは登録できません。上のように255文字を超えないように、区切りダブルクオテーション (“) で囲んで、半角スペースで連結して登録します。
登録する公開鍵レコードは次のようになります。
default._domainkey.zoah.net. IN TXT "v=DKIM1; k=rsa;""p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAhPjDVIuuuF5TGVCW/U1+TKGj3khf8i8rZlTlgTDrvqcRQKLJERwWeagxzS4sbUcU/9WVPRGeUbQQ+IJdwgQ9Ia5g7h1rjcybpyNgp2iNSXfOz/l/K5tbRR0kLIapmY8Grp9Kt4D8Z7R/3X2ftGs1VQL+B72ZGIy9ZhzuSPSI/0DHjvaI2V4qfudsnmbnF54tbEL0L67zy63Osk""N0cNifqJziwuXyaKKezFsb5KIPoW2dagAs/KNdbleptahmGbG22KL+WJQEP2gUdaX9sTyeKWrwJhi1M8TujLcvX77zIBusHzv14ku296k4gUptYQfF5n/hzjJ35vHCA7lseqHnTQIDAQAB"
ADSP レコードの書式
ADSPレコードは、受信側でDKIMの認証結果をどのように扱ってほしいかを示す為のレコードです。dkim=の値は、 all , unknown , discardable のいずれかを設定します。
_adsp._domainkey.＜ドメイン名＞. IN TXT “dkim=＜値＞”
all： このドメインから送信されるメールは、すべてメール作成者署名が与えられる
unknown： このドメインから送信されるメールのいくつか、又は全てに、メール作成者署名が得られる
discardable： このドメインから送信されるメールは、すべてメール作成者署名が与えられる。そして、もしメール作成者署名が得られない場合は、受信者はそのメールを破棄することが望まれる
dkim=unknown とするのが無難なようです。
登録するADSPレコードは次のようになります。
_adsp._domainkey.zoah.net. IN TXT dkim=unknown
OpenDKIM の設定
[root@server1 ~]# vi /etc/opendkim.conf
## BASIC OPENDKIM CONFIGURATION FILE ## See opendkim.conf(5) or /usr/share/doc/opendkim/opendkim.conf.sample for more ## BEFORE running OpenDKIM you must: ## - make your MTA (Postfix, Sendmail, etc.) aware of OpenDKIM ## - generate keys for your domain (if signing) ## - edit your DNS records to publish your public keys (if signing) ## See /usr/share/doc/opendkim/INSTALL for detailed instructions. ## DEPRECATED CONFIGURATION OPTIONS ## ## The following configuration options are no longer valid. They should be ## removed from your existing configuration file to prevent potential issues. ## Failure to do so may result in opendkim being unable to start. ## ## Removed in 2.10.0: ## AddAllSignatureResults ## ADSPAction ## ADSPNoSuchDomain ## BogusPolicy ## DisableADSP ## LDAPSoftStart ## LocalADSP ## NoDiscardableMailTo ## On-PolicyError ## SendADSPReports ## UnprotectedPolicy ## CONFIGURATION OPTIONS ## Specifies the path to the process ID file. #PidFile /run/opendkim/opendkim.pid ## Selects operating modes. Valid modes are s (sign) and v (verify). Default is v. ## Must be changed to s (sign only) or sv (sign and verify) in order to sign outgoing ## messages. Mode sv ← 「s」送信時の署名、及び「v」受信の確認の両方を行います。 ## Log activity to the system log. Syslog yes ## Log additional entries indicating successful signing or verification of messages. SyslogSuccess yes ## If logging is enabled, include detailed logging about why or why not a message was ## signed or verified. This causes an increase in the amount of log data generated ## for each message, so set this to No (or comment it out) if it gets too noisy. LogWhy yes ## Attempt to become the specified user before starting operations. UserID opendkim:opendkim ## Create a socket through which your MTA can communicate. Socket inet:8891@localhost ← このように編集します。 #Socket local:/run/opendkim/opendkim.sock ## Required to use local socket with MTAs that access the socket as a non- ## privileged user (e.g. Postfix) Umask 002 ## This specifies a text file in which to store DKIM transaction statistics. ## OpenDKIM must be manually compiled with --enable-stats to enable this feature. # Statistics /var/spool/opendkim/stats.dat ## Specifies whether or not the filter should generate report mail back ## to senders when verification fails and an address for such a purpose ## is provided. See opendkim.conf(5) for details. SendReports yes ## Specifies the sending address to be used on From: headers of outgoing ## failure reports. By default, the e-mail address of the user executing ## the filter is used (executing_user@hostname). # ReportAddress "Example.com Postmaster" <postmaster@example.com> ## Add a DKIM-Filter header field to messages passing through this filter ## to identify messages it has processed. SoftwareHeader yes ← このように編集します。 ## SIGNING OPTIONS ## Selects the canonicalization method(s) to be used when signing messages. Canonicalization relaxed/relaxed ← このように編集します。 ## Domain(s) whose mail should be signed by this filter. Mail from other domains will ## be verified rather than being signed. Uncomment and use your domain name. ## This parameter is not required if a SigningTable is in use. # Domain example.com ## Defines the name of the selector to be used when signing messages. Selector default ← このように編集します。 ## Specifies the minimum number of key bits for acceptable keys and signatures. MinimumKeyBits 1024 ## Gives the location of a private key to be used for signing ALL messages. This ## directive is ignored if KeyTable is enabled. #KeyFile /etc/opendkim/keys/default.private ← コメントアウトします。 ## Gives the location of a file mapping key names to signing keys. In simple terms, ## this tells OpenDKIM where to find your keys. If present, overrides any KeyFile ## directive in the configuration file. Requires SigningTable be enabled. KeyTable /etc/opendkim/KeyTable ← このように編集します。 ## Defines a table used to select one or more signatures to apply to a message based ## on the address found in the From: header field. In simple terms, this tells ## OpenDKIM how to use your keys. Requires KeyTable be enabled. SigningTable refile:/etc/opendkim/SigningTable ← このように編集します。 ## Identifies a set of "external" hosts that may send mail through the server as one ## of the signing domains without credentials as such. ExternalIgnoreList refile:/etc/opendkim/TrustedHosts ← このように編集します。 ## Identifies a set "internal" hosts whose mail should be signed rather than verified. InternalHosts refile:/etc/opendkim/TrustedHosts ← このように編集します。 ## Contains a list of IP addresses, CIDR blocks, hostnames or domain names ## whose mail should be neither signed nor verified by this filter. See man ## page for file format. # PeerList X.X.X.X ## Always oversign From (sign using actual From and a null From to prevent ## malicious signatures header fields (From and/or others) between the signer ## and the verifier. From is oversigned by default in the Fedora package ## because it is often the identity key used by reputation systems and thus ## somewhat security sensitive. OversignHeaders From ## Instructs the DKIM library to maintain its own local cache of keys and ## policies retrieved from DNS, rather than relying on the nameserver for ## caching service. Useful if the nameserver being used by the filter is ## not local. # QueryCache yes
/etc/opendkim/KeyTable に署名に使う秘密鍵を指定します。書式は次の通りです。
＜セレクタ名＞._domainkey.＜ドメイン名＞ ＜ドメイン名＞:＜セレクタ名＞:＜秘密鍵ファイルのフルパス＞
実際の指定は次のようになります。
[root@server1 ~]# vi /etc/opendkim/KeyTable
default._domainkey.zoah.net zoah.net:default:/etc/opendkim/keys/zoah.net/default.private
/etc/opendkim/SigningTable に署名を行うドメイン名を指定します。書式は次の通りです。
*@＜ドメイン名＞ ＜セレクタ名＞._domainkey.＜ドメイン名＞
実際の指定は次のようになります。
[root@server1 ~]# vi /etc/opendkim/SigningTable
*@zoah.net default._domainkey.zoah.net
[root@server1 ~]# systemctl start opendkim ← OpenDKIM を起動します。
[root@server1 ~]# systemctl enable opendkim ← OpenDKIM を自動的に起動するように設定します。
OpenDMARC の設定
DNSサーバーにDMARCレコードを追加します。
_dmarc.zoah.net. IN TXT "v=DMARC1; p=quarantine; pct=100; adkim=r; aspf=r"
zoah.net は各自のドメインネームに置き換えて下さい。
p= の値は、none (何もしない) , quarantine (隔離する) , reject (拒否する)のいずれを指定します。
adkim= の値は、オプション(デフォルト値は r )。DKIM認証の調整パラメータで、r (relaxed) または s (strict) が指定できます。 s を指定した場合、DKIM の送信ドメイン (dタグ）と Header-From は同じドメインでなければなりません。 r を指定した場合、DKIM の送信ドメイン (dタグ）の サブドメインを Header-From に使用することができます。 例えば、d=@zoah.net, Header-From=@a.zoah.net である場合、s を指定すると認証失敗となりますが、r を指定すると認証成功となります。
aspf= の値は、オプション(デフォルト値は r )。SPF認証の調整パラメータで、r (relaxed) または s (strict) が指定出来ます。 s を指定した場合、Envelope-From と Header-From は同じドメインでなければなりません。 r を指定した場合、Header-Fromのサブドメインを Envelope-From に使用することができます。 前述の通り、メール配信サービスを利用する場合、r として Envelope-From にはサブドメインを使用します。
[root@server1 ~]# dnf install opendmarc ← パッケージをインストールします。
[root@server1 ~]# vi /etc/opendkim.conf ← OpenDMARC の設定ファイルを編集します。
## opendmarc.conf -- configuration file for OpenDMARC filter
##
## Copyright (c) 2012-2015, 2018, 2021, The Trusted Domain Project.
## All rights reserved.
## DEPRECATED CONFIGURATION OPTIONS
##
## The following configuration options are no longer valid. They should be
## removed from your existing configuration file to prevent potential issues.
## Failure to do so may result in opendmarc being unable to start.
##
## Renamed in 1.3.0:
## ForensicReports became FailureReports
## ForensicReportsBcc became FailureReportsBcc
## ForensicReportsOnNone became FailureReportsOnNone
## ForensicReportsSentBy became FailureReportsSentBy
## CONFIGURATION OPTIONS
## AuthservID (string)
## defaults to MTA name
##
## Sets the "authserv-id" to use when generating the Authentication-Results:
## header field after verifying a message. If the string "HOSTNAME" is
## provided, the name of the host running the filter (as returned by the
## gethostname(3) function) will be used.
#
AuthservID server1.zoah.net ← メールサーバー名を指定します。
## AuthservIDWithJobID { true | false }
## default "false"
##
## If "true", requests that the authserv-id portion of the added
## Authentication-Results header fields contain the job ID of the message
## being evaluated.
#
# AuthservIDWithJobID false
## AutoRestart { true | false }
## default "false"
##
## Automatically re-start on failures. Use with caution; if the filter fails
## instantly after it starts, this can cause a tight fork(2) loop.
#
# AutoRestart false
## AutoRestartCount n
## default 0
##
## Sets the maximum automatic restart count. After this number of automatic
## restarts, the filter will give up and terminate. A value of 0 implies no
## limit.
#
# AutoRestartCount 0
## AutoRestartRate n/t[u]
## default (no limit)
##
## Sets the maximum automatic restart rate. If the filter begins restarting
## faster than the rate defined here, it will give up and terminate. This
## is a string of the form n/t[u] where n is an integer limiting the count
## of restarts in the given interval and t[u] defines the time interval
## through which the rate is calculated; t is an integer and u defines the
## units thus represented ("s" or "S" for seconds, the default; "m" or "M"
## for minutes; "h" or "H" for hours; "d" or "D" for days). For example, a
## value of "10/1h" limits the restarts to 10 in one hour. There is no
## default, meaning restart rate is not limited.
#
# AutoRestartRate n/t[u]
## Background { true | false }
## default "true"
##
## Causes opendmarc to fork and exits immediately, leaving the service
## running in the background.
#
# Background true
## BaseDirectory (string)
## default (none)
##
## If set, instructs the filter to change to the specified directory using
## chdir(2) before doing anything else. This means any files referenced
## elsewhere in the configuration file can be specified relative to this
## directory. It's also useful for arranging that any crash dumps will be
## saved to a specific location.
#
# BaseDirectory /var/run/opendmarc
## ChangeRootDirectory (string)
## default (none)
##
## Requests that the operating system change the effective root directory of
## the process to the one specified here prior to beginning execution.
## chroot(2) requires superuser access. A warning will be generated if
## UserID is not also set.
#
# ChangeRootDirectory /var/chroot/opendmarc
## CopyFailuresTo (string)
## default (none)
##
## Requests addition of the specified email address to the envelope of
## any message that fails the DMARC evaluation.
#
# CopyFailuresTo postmaster@localhost
## DomainWhitelist (string)
## default (none)
##
## A brief list of whitelisted domains for which ARC signature headers are
## trusted as determined by evaluating entries in the "arc.chain" field found
## in a locally generated Authentication-Results header.
##
## This list will be concatenated with DomainWhitelistFile (if provided).
##
#
# DomainWhitelist example.com
## DomainWhitelistFile path
## default (none)
##
## A comprehensive list of whitelisted domains for which ARC signature headers
## are trusted as determined by evaluating entries in the "arc.chain" field
## found in a locally generated Authentication-Results header.
##
## This list will be concatenated with DomainWhitelist (if provided).
##
#
# DomainWhitelistFile /etc/opendmarc/whitelist.domains
## DomainWhitelistSize
## default 3000
##
## The maximum number of entries in the DomainWhitelist including both entries
## in the DomainWhitelist configuration parameter (above) and entries in the
## DomainWhitelistFile. This number will be increased by approximately 20% to
## increase the efficiency of the hashing algorithm.
##
#
# DomainWhitelistSize 3000
## DNSTimeout (integer)
## default 5
##
## Sets the DNS timeout in seconds. A value of 0 causes an infinite wait.
## (NOT YET IMPLEMENTED)
#
# DNSTimeout 5
## EnableCoredumps { true | false }
## default "false"
##
## On systems that have such support, make an explicit request to the kernel
## to dump cores when the filter crashes for some reason. Some modern UNIX
## systems suppress core dumps during crashes for security reasons if the
## user ID has changed during the lifetime of the process. Currently only
## supported on Linux.
#
# EnableCoreDumps false
## FailureReports { true | false }
## default "false"
##
## Enables generation of failure reports when the DMARC test fails and the
## purported sender of the message has requested such reports. Reports are
## formatted per RFC6591.
#
# FailureReports false
## FailureReportsBcc (string)
## default (none)
##
## When failure reports are enabled and one is to be generated, always
## send one to the address(es) specified here. If a failure report is
## requested by the domain owner, the address(es) are added in a Bcc: field.
## If no request is made, they address(es) are used in a To: field. There
## is no default.
#
# FailureReportsBcc postmaster@example.coom
## FailureReportsOnNone { true | false }
## default "false"
##
## Supplements the "FailureReports" setting by generating reports for
## domains that advertise "none" policies. By default, reports are only
## generated (when enabled) for sending domains advertising a "quarantine"
## or "reject" policy.
#
# FailureReportsOnNone false
## FailureReportsSentBy string
## default "USER@HOSTNAME"
##
## Specifies the email address to use in the From: field of failure
## reports generated by the filter. The default is to use the userid of
## the user running the filter and the local hostname to construct an
## email address. "postmaster" is used in place of the userid if a name
## could not be determined.
#
# FailureReportsSentBy USER@HOSTNAME
## HistoryFile path
## default (none)
##
## If set, specifies the location of a text file to which records are written
## that can be used to generate DMARC aggregate reports. Records are groups
## of rows containing information about a single received message, and
## include all relevant information needed to generate a DMARC aggregate
## report. It is expected that this will not be used in its raw form, but
## rather periodically imported into a relational database from which the
## aggregate reports can be extracted by a tool such as opendmarc-import(8).
#
# HistoryFile /var/spool/opendmarc/opendmarc.dat
## HoldQuarantinedMessages { true | false }
## default "false"
##
## If set, the milter will signal to the mta that messages with
## p=quarantine, which fail dmarc authentication, should be held in
## the MTA's "Hold" or "Quarantine" queue. The name varies by MTA.
## If false, messsages will be accepted and passed along with the
## regular mail flow, and the quarantine will be left up to downstream
## MTA/MDA/MUA filters, if any, to handle by re-evaluating the headers,
## including the Authentication-Results header added by OpenDMARC
#
# HoldQuarantinedMessages false
## IgnoreAuthenticatedClients { true | false }
## default "false"
##
## If set, causes mail from authenticated clients (i.e., those that used
## SMTP AUTH) to be ignored by the filter.
#
IgnoreAuthenticatedClients true ← このように編集します。
## HoldQuarantinedMessages { true | false }
## default "false"
##
## If set, the milter will signal to the mta that messages with
## p=quarantine, which fail dmarc authentication, should be held in
## the MTA's "Hold" or "Quarantine" queue. The name varies by MTA.
## If false, messsages will be accepted and passed along with the
## regular mail flow, and the quarantine will be left up to downstream
## MTA/MDA/MUA filters, if any, to handle by re-evaluating the headers,
## including the Authentication-Results header added by OpenDMARC
#
# HoldQuarantinedMessages false
## IgnoreHosts path
## default (internal)
##
## Specifies the path to a file that contains a list of hostnames, IP
## addresses, and/or CIDR expressions identifying hosts whose SMTP
## connections are to be ignored by the filter. If not specified, defaults
## to "127.0.0.1" only.
#
IgnoreHosts /etc/opendmarc/ignore.hosts ← このように編集します。
## IgnoreMailFrom domain[,...]
## default (none)
##
## Gives a list of domain names whose mail (based on the From: domain) is to
## be ignored by the filter. The list should be comma-separated. Matching
## against this list is case-insensitive. The default is an empty list,
## meaning no mail is ignored.
#
# IgnoreMailFrom example.com
## MilterDebug (integer)
## default 0
##
## Sets the debug level to be requested from the milter library.
#
# MilterDebug 0
## PidFile path
## default (none)
##
## Specifies the path to a file that should be created at process start
## containing the process ID.
#
# PidFile /var/run/opendmarc.pid
## PublicSuffixList path
## default (none)
##
## Specifies the path to a file that contains top-level domains (TLDs) that
## will be used to compute the Organizational Domain for a given domain name,
## as described in the DMARC specification. If not provided, the filter will
## not be able to determine the Organizational Domain and only the presented
## domain will be evaluated. This file should be periodically updated.
## One location to retrieve the file from is https://publicsuffix.org/list/
#
# PublicSuffixList path
## RecordAllMessages { true | false }
## default "false"
##
## If set and "HistoryFile" is in use, all received messages are recorded
## to the history file. If not set (the default), only messages for which
## the From: domain published a DMARC record will be recorded in the
## history file.
#
# RecordAllMessages false
## RejectFailures { true | false }
## default "false"
##
## If set, messages will be rejected if they fail the DMARC evaluation, or
## temp-failed if evaluation could not be completed. By default, no message
## will be rejected or temp-failed regardless of the outcome of the DMARC
## evaluation of the message. Instead, an Authentication-Results header
## field will be added.
#
RejectFailures false ← このように編集します。
## RejectMultiValueFrom { true | false }
## default "false"
##
## If set, messages with multiple addresses in the From: field of the message
## will be rejected unless all domains in the field are the same. They will
## otherwise be ignored by the filter (the default).
#
# RejectMultiValueFrom false
## ReportCommand string
## default "/usr/sbin/sendmail -t"
##
## Indicates the shell command to which failure reports should be passed for
## delivery when "FailureReports" is enabled.
#
# ReportCommand /usr/sbin/sendmail -t
## RequiredHeaders { true | false }
## default "false"
##
## If set, the filter will ensure the header of the message conforms to the
## basic header field count restrictions laid out in RFC5322, Section 3.6.
## Messages failing this test are rejected without further processing. A
## From: field from which no domain name could be extracted will also be
## rejected.
#
RequiredHeaders true ← このように編集します。
## Socket socketspec
## default (none)
##
## Specifies the socket that should be established by the filter to receive
## connections from sendmail(8) in order to provide service. socketspec is
## in one of two forms: local:path, which creates a UNIX domain socket at
## the specified path, or inet:port[@host] or inet6:port[@host] which creates
## a TCP socket on the specified port for the appropriate protocol family.
## If the host is not given as either a hostname or an IP address, the
## socket will be listening on all interfaces. This option is mandatory
## either in the configuration file or on the command line. If an IP
## address is used, it must be enclosed in square brackets.
#
Socket inet:8893@localhost ← このように編集します。
#Socket local:/run/opendmarc/opendmarc.sock ← コメントアウトします。
## SoftwareHeader { true | false }
## default "false"
##
## Causes the filter to add a "DMARC-Filter" header field indicating the
## presence of this filter in the path of the message from injection to
## delivery. The product's name, version, and the job ID are included in
## the header field's contents.
#
SoftwareHeader true ← このように編集します。
## SPFIgnoreResults { true | false }
## default "false"
##
## Causes the filter to ignore any SPF results in the header of the
## message. This is useful if you want the filter to perform SPF checks
## itself, or because you don't trust the arriving header.
#
SPFIgnoreResults true ← このように編集します。
## SPFSelfValidate { true | false }
## default false
##
## Enable internal spf checking with --with-spf
## To use libspf2 instead: --with-spf --with-spf2-include=path --with-spf2-lib=path
##
## Causes the filter to perform a fallback SPF check itself when
## it can find no SPF results in the message header. If SPFIgnoreResults
## is also set, it never looks for SPF results in headers and
## always performs the SPF check itself when this is set.
#
SPFSelfValidate true ← このように編集します。
## Syslog { true | false }
## default "false"
##
## Log via calls to syslog(3) any interesting activity.
#
Syslog true
## SyslogFacility facility-name
## default "mail"
##
## Log via calls to syslog(3) using the named facility. The facility names
## are the same as the ones allowed in syslog.conf(5).
#
# SyslogFacility mail
## TrustedAuthservIDs string
## default HOSTNAME
##
## Specifies one or more "authserv-id" values to trust as relaying true
## upstream DKIM and SPF results. The default is to use the name of
## the MTA processing the message. To specify a list, separate each entry
## with a comma. The key word "HOSTNAME" will be replaced by the name of
## the host running the filter as reported by the gethostname(3) function.
#
# TrustedAuthservIDs HOSTNAME
## UMask mask
## default (none)
##
## Requests a specific permissions mask to be used for file creation. This
## only really applies to creation of the socket when Socket specifies a
## UNIX domain socket, and to the HistoryFile and PidFile (if any); temporary
## files are normally created by the mkstemp(3) function that enforces a
## specific file mode on creation regardless of the process umask. See
## umask(2) for more information.
#
UMask 007
## UserID user[:group]
## default (none)
##
## Attempts to become the specified userid before starting operations.
## The process will be assigned all of the groups and primary group ID of
## the named userid unless an alternate group is specified.
#
UserID opendmarc:mail ← このように編集します。
[root@server1 ~]# mkdir /etc/opendmarc ← opendmarc ディレクトリを作成します。
[root@server1 ~]# /etc/opendmarc/ignore.hosts ← ignore.hosts ファイルを編集します。
localhost ::1 127.0.0.0/8 192.168.100.0/24 ← 各自の環境に合わせて設定して下さい。
[root@server1 ~]# systemctl restart opendmarc ← opendmarc を再起動します。
[root@server1 ~]# systemctl enable opendmarc ← opendmarc を自動的に起動するように設定します。
[root@server1 ~]# vi /etc/postfix/main.cf ← Postfix の設定ファイルを編集します。
以下のように設定します。
milter_default_action = accept milter_protocol = 6 smtpd_milters = inet:localhost:8891,inet:localhost:8893 non_smtpd_milters = $smtpd_milters
[root@server1 ~]# systemctl restart postfix ← postfix を再起動します。