postfixの設定（gmailでの送信編）

◻️selinuxをoffにする

◻️firewalldの設定見直す。

◻️インストールを行う。

yum -y install cyrus-sasl-plain cyrus-sasl-md5

yum -y install cyrus-sasl

yum -y install postfix

yum -y install dovecot

◻️main.cfの設定を行う。

vi /etc/postfix/main.cf

======== main.cf =============================

# 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/.

#

# For best results, change no more than 2-3 parameters at a time,

# and test if Postfix still works after every change.

# 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 = virtual.domain.tld

myhostname = mail.digihide-test.com

# 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 = domain.tld

mydomain = digihide-test.com

# 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

myorigin = $mydomain

# 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

# Enable IPv4, and IPv6 if supported

inet_protocols = all

# 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.  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

#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 does 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

# 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]

#gmail テスト送信用（通常は、使用しない！！）
relayhost = [smtp.gmail.com]:587

# 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/

home_mailbox = Maildir/

# 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"

# 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

# 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 sesssion, 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-2.10.1/samples

# readme_directory: The location of the Postfix README files.

#

readme_directory = /usr/share/doc/postfix-2.10.1/README_FILES

###########  add settings  ##################

local_recipient_maps =

luser_relay = unknown_user@localhost

# VRFYコマンドの使用を禁止する

disable_vrfy_command = yes

# MailBoxの最大サイズの指定

mailbox_size_limit = 204800000

# 接続元の制限（スパムメール対策）

smtpd_client_restrictions =

    check_client_access hash:/etc/postfix/access

    reject_rbl_client zen.spamhaus.org

    reject_non_fqdn_sender

    reject_unknown_sender_domain

# エンベロープアドレス(MAIL FROM)による制限（スパムメール対策）

smtpd_sender_restrictions =

        reject_rhsbl_sender zen.spamhaus.org

        reject_unknown_sender_domain

########## SMTP-Auth関連 ##########

# SASL認証を有効化

smtpd_sasl_auth_enable = yes

# Dovecot SASL ライブラリを指定

smtpd_sasl_type = dovecot

# Dovecot SASL ライブラリの認証ソケットファイル　/var/spool/postfix/ からの相対パスで記述

smtpd_sasl_path = private/auth

# 古いバージョンの AUTH コマンド (RFC 2554) を実装した SMTP クライアントとの相互運用性を有効にする

broken_sasl_auth_clients = yes

# SASL Authentication

smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd

smtp_sasl_security_options = noanonymous

smtp_sasl_mechanism_filter = plain

# TLS Settings

smtp_use_tls = yes

smtp_tls_security_level = encrypt

tls_random_source = dev:/dev/urandom

#Gmail

smtp_tls_CApath = /etc/pki/tls/certs/ca-bundle.crt

smtp_sasl_auth_enable = yes

smtp_sasl_tls_security_options = noanonymous

########## TLS/SSL関連 ##########

# TLSを有効化

smtpd_use_tls = yes

# 宛先のメールサーバがTLSに対応していれば、通信を暗号化する

smtp_tls_security_level = may

# サーバ証明書と秘密鍵を指定（letsencryptを使用する場合）

smtpd_tls_cert_file = /etc/letsencrypt/live/mail.digihide-test.com/fullchain.pem

smtpd_tls_key_file = /etc/letsencrypt/live/mail.digihide-test.com/privkey.pem

# TLSログレベルの設定

# 0:出力しない　1:TLSハンドシェイクと証明書情報　2:TLSネゴシエーションの全て

smtpd_tls_loglevel = 1

# 暗号に関する情報を "Received:" メッセージヘッダに含める

smtpd_tls_received_header = yes

# 接続キャッシュファイルの指定

smtpd_tls_session_cache_database = btree:/var/lib/postfix/smtpd_scache

# キャッシュの保持時間の指定

smtpd_tls_session_cache_timeout = 3600s

# 認証を通過したものはリレーを許可する（permit_sasl_authenticated）

smtpd_sasl_auth_enable = yes

smtpd_recipient_restrictions =

    permit_mynetworks

    permit_sasl_authenticated

    reject_unauth_destination

=======================================================================

◻️saslのパスワードの設定を行う。

vi /etc/postfix/sasl_passwd

==============sasl_passwd====================

[smtp.gmail.com]:587 gmailのアドレス:<パスワード>

=============================================

chmod 600 /etc/postfix/sasl_passwd

postmap hash:/etc/postfix/sasl_passwd

◻️googleアカウントの

安全性の低いアプリの許可: 無効にすること。

注意：ただし、テスト送信が済んだら元に戻すことを進める!!

◻️テスト送信を以下のコマンドで行ってみる。

sendmail gmailのメールアドレス

Subject: test

メッセージを入力

.

上記によって、テスト送信ができるはず。