Overview
By default, Exim sends mail from the server’s primary IPv4 address. To decrease the chance that spam filters mark your mail as spam, verify that the reverse DNS (rDNS) entry of Exim’s outgoing IP address matches the DNS response of your server’s hostname.
Note:
The steps in this document require root
-level privileges on the server.
Modify Exim’s preferences for outgoing mail
cPanel & WHM offers two ways by which to modify Exim’s default preferences for outgoing mail’s IP address.
Enable automatic configuration of the server’s IPv4 address for outgoing mail
To automatically configure Exim to send mail from each domain’s dedicated IPv4 address, perform the following steps:
- Modify the rDNS for each IPv4 address to point to the desired domain.
Important:
- An incorrect rDNS configuration may cause mail servers to reject your server’s mail.
- For more information, read our How to Configure Reverse DNS for BIND in WHM documentation.
- Enable the Send mail from account’s dedicated IP address option in WHM’s Exim Configuration Manager interface ( Home >> Service Configuration >> Exim Configuration Manager ).
Warning:
If you select this option, cPanel & WHM uses the
/usr/local/cpanel/scripts/updateuserdomains
script to automatically configure Exim, and overrides any manual changes in the following files:-
/etc/mailhelo
/etc/mailips
-
Manually configure Exim’s outgoing IP addresses
Important:
- We do not recommend that you modify your Exim files.
- To modify your Exim configuration files, you must possess
root
-level privileges.
To use a custom Exim configuration, you must enable the following options in the Basic Editor section of WHM’s Exim Configuration Managerinterface (Home >> Service Configuration >> Exim Configuration Manager):
- Reference /etc/mailhelo for outgoing SMTP HELO
- Reference /etc/mailips for outgoing SMTP connections
Important:
- If you disable the Reference /etc/mailhelo for outgoing SMTP HELO setting, the system will overwrite any changes that you make to the
/etc/mailhelo
file. - If you disable the Reference /etc/mailips for outgoing SMTP connections setting, the system will overwrite any changes that you make to the
/etc/mailips
file.
The /etc/mailhelo
file
The /etc/mailhelo
file contains Exim’s configuration for the HELO
command, which initiates dialog between a mail server and a client. This file governs which domain sends the HELO
command.
Use your preferred text editor to create an /etc/mailhelo
file that resembles the following example:
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2
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5
|
example.com: example.com sub.example.com: example.com example.net: example.net addon.example.net: example.net *: hostname .example.com |
The /etc/mailips file
The /etc/mailips
file controls the IP address from which each domain sends mail.
Use your preferred text editor to create an /etc/mailips
file that resembles one of the following examples: