Procmail is a versatile e-mail processor that can be used to sort your incoming mail. You configure it by creating a ~/.procmailrc file. It's described by some rather complicated manpages, so people have put together:

• a quick start guide

• a cookbook

• a How to filter guide

Sample

Here is a sample ~/.procmailrc file that you can use to weed out duplicate mail and throw away extra mail from ubuntu-bugs.

# Set to yes when debugging
VERBOSE=yes

# Default INBOX
INBOX=$MAIL

# Directory for storing procmail-related files
PMDIR=$HOME/procmail

# Uncomment the following line to get logging
#LOGFILE=$PMDIR/log

# Eliminate duplicates
:0 Wh: .msgid.lock
| formail -D 8192 $PMDIR/.msgid.cache

# Only keep ubuntu-bugs mail that announces newly reported bugs.
:0
* ^TO_ubuntu-bugs@lists\.ubuntu\.com
* ^X-Launchpad-Bug:
{
  :0 B
  * ^Public bug reported:
  $INBOX
  :0
  /dev/null
}

# Add all the rest to my inbox
:0
$INBOX