During my absence, our outgoing Exim mail servers where blacklisted at spamcop.net, obviously causing outgoing messages to be refused by all servers who use spamcop.net in their DNSBL. My ersatz--postmaster called me on the phone, and I suggested the listing must be due to an observed increase in collateral spam being caused by idiotic Lotus Notes out of office agents which offer an answer to any email for the asking 1. I was right: a message to the friendly people of spamcop.net turned up two sample messages which were in fact Lotus out-of-office messages. The first big task on my todo-list is to get management to agree to disable out-of-office (vacation) agents for all users until I can come up with a solution. It is going to be a bit tricky because, as mentioned below, I may not turn on anti-spam for all users. We've already come up with a method of identifying out-of-office mails (small addition to the users' mail template), but then I still have to correlate those to original incoming messages... 1 Due to German law, we must let in all mail without passing it through an anti-spam filter unless the user explicitly opts-in to anti-spam checking. Since most users are not bothered too much with spam, they never get around to signing up for anti- spam, therewith causing spam to be delivered to Lotus Domino where it triggers the OOO agent.