• i-MSCP versions >= 1.1.0.rc4.7
• opendkim opendkim-tools Debian package

• apt-get opendkim opendkim-tools

• Login into the panel as admin and go to the plugin management interface
• Upload the OpenDKIM plugin archive
• Activate the plugin

• Backup your current plugins/OpenDKIM/config.php file
• Login into the panel as admin and go to the plugin management interface
• Upload the OpenDKIM plugin archive
• Restore your plugins/OpenDKIM/config.php file (check for any change)
• Update the plugin list through the plugin interface

Edit the plugins/OpenDKIM/config.php:

• opendkim_port ⇒ Port for the OpenDKIM daemon (don't use ports lower than 1000 and greater than 65535)
• opendkim_canonicalization ⇒ See code box below

Select the canonicalization method(s) to be used when signing messages. When verifying, the message's DKIM-Signature: header field specifies the canonicalization method. The recognized values are relaxed and simple as defined by the DKIM specification. The value may include two different canonicalizations separated by a slash ("/") character, in which case the first will be applied to the header and the second to the body. allowed values: simple (default), relaxed, simple/relaxed, relaxed/simple

• opendkim_trusted_hosts ⇒ Add domains which should be considered as trusted hosts by OpenDKIM