For anyone still wondering, since it isn't addressed in the Moderators note linked in the first post.
This is relatively easy to fix. However, there is no way to do it without root access. Goes without saying that cPanel likely wont recommend or support it.
You need to modify the Exim Configuration file and change the
smtp_banner line(s) to make use of a lookup. We also need to manually create a file to act as our lookup database.
First, create the lookup file at
/etc/exim_banner_addresses and place each mapping on its own line using the following format:
Code:
192.168.1.234: myhost.domain.tld
10.1.2.3: host2.domain.tld
Now edit the exim config, found at:
/etc/exim.conf
Search for the following lines:
Code:
smtp_banner = "${primary_hostname} ESMTP Exim ${version_number} \
\#${compile_number} ${tod_full} \n\
We do not authorize the use of this system to transport unsolicited, \n\
and/or bulk e-mail."
Replace the above lines with these:
Code:
smtp_banner = "${smtp_active_hostname}"
smtp_active_hostname = ${lookup{$interface_address}lsearch{/etc/exim_banner_addresses}{$value}{$primary_hostname}}
Save the changes, and restart Exim to see the results.
You may also want to set the config file to read-only.
Again, this is not an automatic solution. In addition to manually adding new mapping entries - you will likely need to verify updates to Exim don't also require config updates, or need to manually re-apply this patch from time to time.
One could think cPanel would already support this along side their other dedicated IP functionality. cPanel is full of stuff like this though. I'd make a feature request but I don't feel like writing a short story to explain it, or waiting months or years for it to gain traction with the devs. I'll leave that to someone who's good at it.
