Local emails going into SPAM

I am seeing lots of emails from my domain is going to sPAM on the same domina .i mean local emails are goin into SPAM on my server ,is some one is facing this kind of issue.

Try this
http://www.zimbra.com/forums/adminis...-1-2010-a.html

Owl700 is probably correct but for future reference please post the headers from one of the email so we are able to take a look and see which rules are being hit.