Very strange log entries!

I have noticed a number of VERY strange log entries (this is 0.53
hpux9.05):

1996-07-26 07:47:08 0ujlMK-0006d8-00 <= owner-wun@??? H=phoenix.grove.net [205.244.12.2] P=smtp S=2808 id=199607261055.MAA25881@???
1996-07-26 07:47:27 0ujlMK-0006d8-00 smtp          25/tcp                 # Simple Mail Transfer Protocol

1996-07-26 07:47:27 0ujlMK-0006d8-00 == Lester.Veenstra@??? <lester.veenstra@???> T=smtp defer (232): Connection reset by peer: smtp          25/tcp                 # Simple Mail Transfer Protocol