Here is a procmail.rc I am using to block non-pg server commit messages:
:0
* ^From:(dot)*(at)pgfoundry\(dot)org
* ^Subject: \[COMMITTERS\]
| cat > /dev/null
--
Bruce Momjian | http://candle.pha.pa.us
pgman(at)candle(dot)pha(dot)pa(dot)us | (610) 359-1001
+ If your life is a hard drive, | 13 Roberts Road
+ Christ can be your backup. | Newtown Square, Pennsylvania 19073