postconf

Wat het doet

Zo schrijf je het

postconf [-n] [-e 'key = value'] [KEY]
postqueue -p | -f ; postsuper -d ID|ALL

Belangrijkste delen

Tools

postconf -n

Show only changed settings.

postconf KEY

Show one setting.

postconf -e 'KEY = VALUE'

Change a setting.

postqueue -p (mailq)

Show the queue.

postqueue -f

Try to send all queued mail now.

postsuper -d ID / -d ALL

Delete mail from the queue.

postcat -q ID

Show a queued mail.

postfix check / reload

Check config / reload.

postmap FILE

Build lookup tables (sasl_passwd, transport).

Meest gebruikt

Niets past bij dit filter.

$ als gewone gebruiker# als root (of met sudo)

1. 1Install and send only from this host

   #dnf install -y postfix s-nail cyrus-sasl-plain
   #postconf -e 'inet_interfaces = loopback-only'
   #systemctl enable --now postfix

2. 2Relay through a smart host with TLS and login

   #postconf -e 'relayhost = [smtp.example.com]:587' 'smtp_tls_security_level = encrypt' 'smtp_sasl_auth_enable = yes' 'smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd' 'smtp_sasl_security_options = noanonymous'
   #echo '[smtp.example.com]:587 alerts@example.com:Example-Only-Pass' > /etc/postfix/sasl_passwd
   #chmod 600 /etc/postfix/sasl_passwd && postmap /etc/postfix/sasl_passwd
   #systemctl reload postfix

3. 3Send a test mail

   $echo "Test from $(hostname)" | mail -s "Postfix test" ops@example.com
   #journalctl -u postfix -n 20

4. 4Look at the queue

   #postqueue -p
   #postcat -q 4F2A91C0D1
   #postqueue -f

5. 5Clean the queue

   #postsuper -d 4F2A91C0D1
   #postsuper -d ALL deferred

6. 6See your changed settings

   #postconf -n

7. 7Check the config

   #postfix check

8. 8Check SPF, DKIM and DMARC of a domain

   $dig +short TXT example.com | grep spf
   $dig +short TXT default._domainkey.example.com
   $dig +short TXT _dmarc.example.com

9. 9Test TLS of a mail server

   $openssl s_client -connect mail.example.com:25 -starttls smtp </dev/null 2>/dev/null | grep -E "subject|issuer|Protocol"

10. 10Find why a mail was not sent

    #grep "status=deferred\|status=bounced" /var/log/maillog | tail -5
    #journalctl -u postfix --since "1 hour ago" | grep -E "status=(deferred|bounced)"

Niets past bij dit filter.

Bestanden

/etc/postfix/main.cf

Main settings.

/etc/postfix/master.cf

Services and ports.

/var/spool/postfix/

Queue.

/var/log/maillog or journal

Logs.

Exitcodes