"Many U*nix users with advanced email needs, a high
load of email, and possibly a lot of addresses to keep separated,
invariably come to procmail and to Mutt (but the MCG concept can be
easily adapted to other MUAs: read on).
"Procmail and Mutt are so flexible and powerful to allow a total
customization of email management, whatever your particular needs
are, and they automatize many tasks. Furthermore, they are much
less resource hungry than many other solution with the same power
and flexibility (do they exist?)"