====== Postfix ======

<code bash>
apt install postfix -y
Internetmail with Smart Host
FQDN meinekleinefarm.net
Relayhost external-relay.de

cp /etc/postfix/main.cf /etc/postfix/main.cf.BAK
nano /etc/postfix/main.cf
</code>
  * <code txt>
smtpd_tls_cert_file=/etc/letsencrypt/live/meinekleinefarm.net/fullchain.pem
smtpd_tls_key_file=/etc/letsencrypt/live/meinekleinefarm.net/privkey.pem
myhostname = mail.meinekleinefarm.net
# mydestination = debian.meinekleinefarm.net, localhost.meinekleinefarm.net, localhost

# Handing off local delivery to Dovecot's LMTP
virtual_transport = lmtp:unix:private/dovecot-lmtp

# Enabling SMTP for authenticated users, and handing off authentication to Dovecot
smtpd_sasl_type = dovecot
smtpd_sasl_path = private/auth
smtpd_sasl_auth_enable = yes
smtpd_tls_auth_only = yes

# Virtual domains, users, and aliases
virtual_mailbox_domains = /etc/postfix/virtual_mailbox_domains
# virtual_mailbox_maps = /etc/postfix/virtual_mailbox_maps
# virtual_alias_maps = hash:/etc/postfix/virtual_alias_maps
# virtual_alias_maps = regexp:/etc/postfix/virtual_alias_global

# relay_recipient_maps = hash:/etc/postfix/relay_recipients
</code>
<code bash>
nano /etc/postfix/virtual_mailbox_domains
</code>
  * <code txt>
meinekleinefarm.net OK
mgs-ullrich.de OK
</code>
<code bash>
postmap /etc/postfix/virtual_mailbox_domains

cp /etc/postfix/master.cf /etc/postfix/master.cf.BAK
nano /etc/postfix/master.cf
</code>
Uncomment Line 17 to activate secure message submission agent (MSA) on port 587
  * <code txt>
submission inet n       -       -       -       -       smtpd
</code>
<code bash>
systemctl restart postfix
</code>