information security services
If your using Gmails SMTP relay and receive either of the following errors, switch your outbound mail to use port 587.
Show Postfix errors; tail -f /var/log/syslog
Look for either of these;delivery temporarily suspended: connect to smtp-relay.gmail.com
delivery temporarily suspended: lost connection with smtp-relay.gmail.com
The fix;vi /etc/postfix/main.cf
Update the realyhost;relayhost = smtp-relay.gmail.com:587
Symptom is no email is being received
tail /var/mail/root contains the following error:
Diagnostic-Code: X-Postfix; unknown user:
When you install postfix if your hostname includes your domain then Postfix thinks its receiving mail for the domain, to fix:
vim /etc/postfix/main.cf
remove [yourdomain.com] from mydestination section
restart postfix and retest
postfix stop
postfix start
Reference:
http://stackoverflow.com/questions/32877196/postfix-thinks-the-system-email-is-local