Linux/Mailserver/Postfix Satellite

Installation

• install postfix

apt-get install postfix

• postfix configuration (automatic during installation or "dpkg-reconfigure postfix")
  • "Satellite System"
  • System-Email-Name: "domain.de"
  • SMTP-Relay-Server: "smtp.domain.de"

Configuration

• /etc/mailname

localhostname.localdomain

• /etc/postfix/main.cf

smtpd_banner = $myhostname ESMTP $mail_name (Ubuntu)
biff = no

append_dot_mydomain = no
#delay_warning_time = 4h
readme_directory = no

# TLS parameters
smtpd_tls_cert_file=/etc/ssl/certs/ssl-cert-snakeoil.pem
smtpd_tls_key_file=/etc/ssl/private/ssl-cert-snakeoil.key
smtpd_use_tls=yes
smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache
smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache

myhostname = localhostname.localdomain
mydomain = localdomain
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases

relayhost = [smtp.domain.de]:submission
mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128
mailbox_size_limit = 0
recipient_delimiter = +
inet_interfaces = loopback-only
inet_protocols = all

recipient_canonical_maps = hash:/etc/postfix/canonical_recipients
sender_canonical_maps = hash:/etc/postfix/canonical_senders

smtp_tls_note_starttls_offer = yes
smtp_tls_security_level = encrypt
smtp_tls_mandatory_ciphers = high

smtp_sasl_auth_enable = yes
smtp_sasl_security_options = noanonymous noplaintext
smtp_sasl_tls_security_options = noanonymous
smtp_sasl_password_maps = hash:/etc/postfix/sasl_password

• create files

touch /etc/postfix/canonical_recipients
touch /etc/postfix/canonical_senders
touch /etc/postfix/sasl_password
chmod 600 /etc/postfix/sasl_password
touch /etc/postfix/reload.sh
chmod 744 /etc/postfix/reload.sh

• /etc/postfix/canonical_recipients

root         server@domain.de
postmaster   root
webmaster    root
user         user@domain.de

• /etc/postfix/canonical_senders

root         hostname@domain.de
postmaster   root
webmaster    root
user         root

• /etc/postfix/sasl_password

[smtp.domain.de]:submission      username:password

• /etc/postfix/reload.sh

#!/bin/bash
newaliases
postmap /etc/postfix/canonical_recipients
postmap /etc/postfix/canonical_senders
postmap hash:/etc/postfix/sasl_password 
/etc/init.d/postfix restart

quick test

echo Emailtext | mail -s "Subject" user@domain.de

Restart

• reload maps

postmap /etc/postfix/canonical_recipients
postmap /etc/postfix/canonical_senders
postmap hash:/etc/postfix/sasl_password 

• restart address mapping

/etc/init.d/postfix restart