/etc/postfix/main.cf

queue_directory = /var/spool/postfix
command_directory = /usr/sbin
daemon_directory = /usr/libexec/postfix
data_directory = /var/lib/postfix
mail_owner = postfix
myhostname = mail.example.com
mydomain = example.com
myorigin = $mydomain
inet_interfaces = all
inet_protocols = all
mydestination = $myhostname, localhost.$mydomain, localhost, $mydomain, seo.$mydomain, lp.$mydomain #サブドメインもここに設定
virtual_alias_domains = website.com
virtual_alias_maps= hash:/etc/postfix/virtual
unknown_local_recipient_reject_code = 550
relay_domains = $mydestination
#relayhost= [mail.example.com]:587 #転送せずにそのまま送信
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
recipient_delimiter = +
home_mailbox = Maildir/
mailbox_command = /usr/bin/procmail
mail_name = unknown
biff = no
append_dot_mydomain = no
debug_peer_level = 2
debugger_command =
         PATH=/bin:/usr/bin:/usr/local/bin:/usr/X11R6/bin
         ddd $daemon_directory/$process_name $process_id & sleep 5
newaliases_path = /usr/bin/newaliases.postfix
mailq_path = /usr/bin/mailq.postfix
setgid_group = postdrop
html_directory = no
manpage_directory = /usr/share/man
sample_directory = /usr/share/doc/postfix-2.10.1/samples

smtpd_banner = $myhostname ESMTP unknown
#smtpd_sasl_type = dovecot
#smtpd_sasl_path = private/auth
smtpd_sasl_auth_enable = yes
smtpd_sasl_local_domain = $mydomain #$myhostname => $mydomain に変更
smtpd_sasl_security_options = noanonymous
broken_sasl_auth_clients = yes
smtp_tls_CAfile = /etc/pki/CA/cacert.pem
smtp_tls_security_level = may
smtp_tls_loglevel = 1
smtpd_tls_cert_file = /etc/pki/CA/certs/mail.example.com.crt
smtpd_tls_key_file = /etc/pki/CA/private/mail.example.com.key
smtpd_tls_session_cache_database = btree:/etc/postfix/smtpd_scache
maps_rbl_reject_code = 550
default_rbl_reply = $rbl_code <$recipient>: Recipient address rejected: User unknown in local recipient tables
smtpd_tls_mandatory_protocols = !SSLv2, !SSLv3
# 10/25 22:10 追加
smtpd_sasl_password_maps = hash:/etc/postfix/sasl_passwd
smtpd_relay_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination
# 迷惑メール対策として、最低でもHELOの応答がない場合は、破棄するようにします。
smtpd_helo_required = yes
# HELO or ELO で応答したホスト名をファイルで検索し、該当する名前があれば、その指示に従うようにします。
smtpd_helo_restrictions = check_helo_access hash:/etc/postfix/helo,permit

## /etc/postfix/virtual
#
# real user: hogehoge
# imaginary user: info1, info2, mail
#

website.com anything
info1@website.com hogehoge

webdesign.com anything
info2@webdesign.com hogehoge
mail@webdesign.com hogehoge
hogehoge@seo.webdesign.com hogehoge

chocolate.com anything
hogehoge@chocolate.com hogehoge
hogehoge@lp.chocolate.com hogehoge


## /etc/postfix/helo
# OK or REJECT
<YOUR IP ADDRESS> OK
200.90.xx.xx REJECT


#REMEMBER
$postmap /etc/postfix/virtual
$postmap /etc/postfix/helo