[Mimedefang] Skip checks for localhost

[Jon Fullmer]

Here's probably a rookie question.  How can I configure Mimedefang to skip
checks for messages originating from localhost?

At a higher level, I have a script that runs on the mail server and
generates e-mail messages to some of my users.  MD keeps rejecting the
message due to "suspicious_chars".  I can't seem to figure out what
characters it has a problem with, so I'm at the point where I want it to
just skip checking the message all together and just SEND the message.

Suggestions?

 - Jon