Fix for Postfix delivery temporarily suspended: Connection timed out mail error
If mails are not getting delivered in a server there postfix is used and you see the following error in log files
postfix/qmgr: 43C11AG313F: firstname.lastname@example.org, relay=none, delay=0, status=deferred (delivery temporarily suspended: connect to <domain name>[ip]: Connection timed out)
the solution would be very simple.
The issue is that firewall/iptables is blocking local relay host 127.0.0.1
So just run the following command and the issue will be solved.
#/sbin/iptables -A INPUT -s 127.0.0.1 -j ACCEPT
#/sbin/iptables -A INPUT -d 127.0.0.1 -j ACCEPT