Howto Change QMail default IP

You have a Plesk server which runs under CentOS and you’ve got spammed from your server, but after you remove them you still find your IP is blocked by many of the blacklists, and this is still an issue for your remaining clients. What could you do next? What you need to do it temporarily change the qmail sender IP address, this is very easy to do. However, it’s temporary, a server reboot will gets everything back to normal state.

For example, say your qmail IP address is 192.168.1.1 and you want to change it to 192.168.2.2. Your gateway is 192.168.1.3 and does not change.

Run command type in:
$ /sbin/ip route

You’ll see this:

192.168.1.4/27 dev eth0 proto kernel scope link src 192.168.1.1
1.1.1.4/24 dev eth1 proto kernel scope link src 1.1.1.1
169.254.0.0/16 dev eth1 scope link
default via 192.168.1.3 dev eth0

To change the default qmail IP from 192.168.1.1 to 192.168.2.2:

Run command type in:
$ /sbin/ip route change default via 192.168.1.3 dev eth0 src 192.168.2.2

That’s all folks. All qmail outgoing mails now leave from IP 192.168.2.2 instead of 192.168.1.1

Hope this will help~