Changing sender IP in Exim

One of the drawbacks of shared hosting is that get punished without doing any sin. It is a common scenario that the shared hosting users often complain about blacklisting of their IP address causing the mails to be bounced. You may surprised by saying you did not do anything such. But yes, it is shared, someone else did that for you . Someone from same server might have sent lots of spam mails, ran darkmailer and finally blacklists the IP address which causes troubles for everyone in that server.

You can change the server’s IP address for sending email. Assuming you already have an IP set up on your server with a valid PTR, you probably already saw on the cPanel forums or some other location that you can simply change the interface lines in your /etc/exim.conf file and restart exim:

remote_smtp:
driver = smtp
interface = ${if exists {/etc/mailips}{${lookup{$sender_address_domain}lsearch*{/etc/mailips}{$value}{}}}{}}
helo_data = ${if exists {/etc/mailhelo}{${lookup{$sender_address_domain}lsearch*{/etc/mailhelo}{$value}{$primary_hostname}}}{$primary_hostname}}

dk_remote_smtp:
driver = smtp
interface = ${if exists {/etc/mailips}{${lookup{$sender_address_domain}lsearch*{/etc/mailips}{$value}{}}}{}}
helo_data = ${if exists {/etc/mailhelo}{${lookup{$sender_address_domain}lsearch*{/etc/mailhelo}{$value}{$primary_hostname}}}{$primary_hostname}}
dk_private_key = “/var/cpanel/domain_keys/private/${dk_domain}”
dk_canon = nofws
dk_selector = default

In the above example, all you’d do is comment out the interface lines and replace them with:

interface = xx.xx.xx.xx

However, this tends to be a band-aid fix, as a cPanel update or any change made in WHM’s Exim Configuration Editor will regenerate the Exim config and overwrite your change. To make this more permanent, you’ll want to use the /etc/mailips file.

To set this up initially, go into WHM > Exim Configuration and enable this option:

** Send outgoing mail from the ip that matches the domain name in /etc/mailips (*: IP can be added to the file to change the main outgoing interface) [?]

Or, in /etc/exim.conf.localopts, add/change this line:

per_domain_mailips=1

Then run

/scripts/buildeximconf
service exim restart

*The /etc/mailips file should be root:exim, chmod 440  if it doesn’t already exist.

chattr +i /etc/mailips

Continue reading….

Related posts:

1. Clean/Flushing Exim mail queue