Changing the IP Per Domain

If you want your users with dedicated IP addresses to be able to use those IPs to send email as well, you can add them to /etc/mailips. cPanel actually now has documentation on how to do this properly:

http://docs.cpanel.net/twiki/bin/view/AllDocumentation/WHMDocs/EximDifferentIps

If you have multiple dedicated IP domains already, I’ve devised a simple loop you can use to populate /etc/mailips automatically:

while read line ; do DOMAINNAME=`echo -e $line |awk '{print $2}'` && IP=`echo -e $line |awk '{print $1}' |cut -d: -f1` && echo "$DOMAINNAME: $IP" >> /etc/mailips ;done < /etc/domainips

Then:

cp /etc/domainips /etc/mail_reverse_dns

This will set all the existing sites on dedicated IPs to send out mail on those IPs.