This used to be my best log:
Dec 11 23:57:24 delilah spamd[32048]: 69.6.40.26: connected (1/1), lists: spamhaus spews1 spews2 Dec 12 00:30:08 delilah spamd[32048]: 69.6.40.26: disconnected after 1964 seconds. lists: spamhaus spews1 spews2
A sender at wholesalebandwidth.com tried a total of 13 times from December 9th through 12th, giving up after one last attempt which lasted 32 minutes, 44 seconds without delivering a message.