I know procmail works, it integrates nicely with sendmail and it never loses mail. Wheras Mail::Audit seems to require being put in a .forward filter which isn't ideal (I think your mail will bounce if your program dies).

Actually you could run Mail::Audit from procmail fairly easily which would probably give the best of both worlds - procmail's facility as a local delivery agent for sendmail with Mail::Audit's perl user friendliness!

I know procmail's syntax is a little arcane - but hey this is Perlmonks - we're used to arcane Syntax!