How to install Domain Keys on a cPanel server

You can install domain keys on a cpanel server easily for a single domain. Run the following command shown below:

/usr/local/cpanel/bin/domain_keys_installer username

It will install for the domain (test.com) successfully. Now you can
verify it from the db record of the domain. The following new entry
will be added in the db record.
vi /var/named/test.com.db

default._domainkey.username IN TXT "k=rsa; p=MHwwDQYJKoZIhvcNAQEBBQADawAwaAJhAOmrn9fVOia0KET1UwIDAQAB;"

rndc reload test.com
Restart exim service.

Now you can verify it by creating a new mail account test123@test.com and send an email to yahoo account, then verify the headers.

Return-Path:   	 	 <test123@test.com>
Authentication-Results:  mta398.mail.re4.yahoo.com from=test.com; domainkeys=pass (ok)
Received: 		 from mta398.mail.re4.yahoo.com with SMTP; Sun, 27 Apr 2008 03:49:29 -0700
DomainKey-Signature:     a=rsa-sha1; q=dns; c=nofws; s=default; d=test.com; 9BZnoI9FAPMSTPY;

From the above headers you can confirm that domain key is working fine for the domain (test.com).

Try:)