Configure Postfix as MX Backup
 

Hi all,

I am fairly new to Linux and I have recently installed a RedHat Linux 8 which I intend to Run Postfix on as an MX backup. I am also new to how email and Postfix works. Configuring Postfix to be an MX backup is easy enough and when I start Postfix it starts up fine plus I can telnet to port 25 on the server. Unfortunately it will not accept mail. Do I have to have either /usr/sbin/ipop3d or /usr/sbin/imapd running too? I also need to know how to create an email address to send test mails to. Can someone please help me with this. If you need more information please don't hesitate to ask. Thanks.

Have you tried issuing commands via the telnet session (mail commands?) and if so what kind of response are you getting?

Telnet to port 25 not working (postfix)
 

Hi Jonasx,

thanks for your reply. When I telnet to port 25 on the server from my command prompt it seems to connect OK except that no header appears and I cannot type anything in. When I go to the server and type in netstat -a | less I can see that I have established a connection. Maybe SMTP isn't working correctly??? I have done a postfix check and it came back OK. No errors starting postfix either. Sendmail has been disabled and uninstalled too so that is not accessing port 25. I have postfix running chrooted. Below id the processes that are running.

tcp 0 20 postfixserver@test.com:ssh joe.test.com:1613 ESTABLISHED
tcp 2 0 postfixserver@test.com:smtp joe.test.com:3335 CLOSE_WAIT
tcp 0 0 postfixserver@test.com:smtp joe.test.com:1290 ESTABLISHED
tcp 25 0 postfixserver@test.com:smtp joe.test.com:2992 CLOSE_WAIT


ps -edaf | grep postfix
root 7214 1 0 11:17 ? 00:00:00 /usr/libexec/postfix/master
postfix 7216 7214 0 11:17 ? 00:00:00 qmgr -l -t fifo -u -c
postfix 7217 7214 0 11:17 ? 00:00:00 cleanup -z -t unix -u -c
postfix 7311 7214 0 11:35 ? 00:00:00 cleanup -z -t unix -u -c
postfix 7389 7214 0 11:53 ? 00:00:00 cleanup -z -t unix -u -c
postfix 7472 7214 0 12:10 ? 00:00:00 cleanup -z -t unix -u -c
postfix 7552 7214 0 12:28 ? 00:00:00 cleanup -z -t unix -u -c
postfix 7632 7214 0 12:46 ? 00:00:00 cleanup -z -t unix -u -c
postfix 7703 7214 0 13:01 ? 00:00:00 proxymap -t unix -u
postfix 7712 7214 0 13:03 ? 00:00:00 cleanup -z -t unix -u -c
postfix 7799 7214 0 13:21 ? 00:00:00 pickup -l -t fifo -u -c
postfix 7800 7214 0 13:21 ? 00:00:00 cleanup -z -t unix -u -c
root 7898 6512 0 13:27 pts/0 00:00:00 grep postfix