Rules for blocking in & out bound mail without address

[keith]

Dear All,
 I have using MS 4.56.7-1 in CentOS 4, I read the google for while but still
can't find how to use MS rules to block or reject the in and out mail with the
sender or receipent address, because I found the mailq have over  6k to 7k
dead mail is such problem , I need to remove them manually, so I think the MS
can handle this job, who can ask to me how to do this.

Thank you .
Keith 
Regards

--