exim paniclog /var/log/exim4/paniclog on church.spirit.org has non-zero size, mail system might be broken. The last 10 lines are quoted below.

2010-04-14 10:22:35 Failed to get user name for uid 1000
2010-04-14 10:22:53 Failed to get user name for uid 1000
2010-04-14 10:23:18 Failed to get user name for uid 1000
2010-04-14 10:23:28 Failed to get user name for uid 1000
2010-04-14 10:25:15 Failed to get user name for uid 1000