Mail::Audit looks interesting but it would
mean ditching procmail which I'd personally find unacceptable.
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!