<b>DKIM information</b>

DKIM will sign outbound message, and receiving servers will check that signature against DNS records added to your zone to verify the signature and lower the spam score if it passes.

Install guide:
http://help.directadmin.com/item.php?id=569

Versions entry:
http://www.directadmin.com/features.php?id=1189

More info on DKIM:
http://wiki.exim.org/DKIM

John