One thing to note: I recommend making extensive use of eval wrapping blocks when using Mail::Audit. This way, you can catch any mishaps and still deliver the mail to a standard inbox. If you're not going through procmail, on some mailservers a failing Mail::Audit filter (I had poorly tested mine for whether the permissions allowed the smptd to run it f.ex) will result in the mail making a trip to the bit bucket - not what you want. It shouldn't be necessary in an ideal world to do so, but generously sprinkling evals followed $mail->accept($default_inbox); all over the place will protect your mail from boneheaded Monday morning mishaps and won't do any harm in other cases.
in reply to A Beginner's Guide to Using Mail::Audit and Mail::SpamAssassin
Makeshifts last the longest.