... is a 
Library for creating easy mail filters. We use it because - like Simon Cozens states it - 
procmail is nasty.
Please read the article 
Mail Filtering with Mail::Audit by Simon Cozens to get an idea what you can do with it.
On 
quepasa, 
Mail::Audit is wrapped through a script called "dispatchmail" using per-user rules from 
$HOME/.dispatchmailrc. This way, you can easily customize your personal mail filtering and sorting.
To actually activate this thing for you, please add this line to your 
.forward file: 
|"/data/opt/dispatchmail/bin/dispatchmail --base=/home/user"
                                                       ^^^^
                                                       |
                                                       your username here!