88 Mail tralia, Britain, France, and all over the U.S. I speculate that the list has at least 200 recipients, and about 25% of them are actually UUCP sites that are MX’d on the Internet. I destroyed about 4,000 copies of the error message in our queues here at Apple Computer. After I turned off our SMTP daemon, our secondary MX sites got whacked. We have a secondary MX site so that when we’re down, someone else will collect our mail in one place, and deliver it to us in an orderly fashion, rather than have every host which has a message for us jump on us the very second that we come back up. Our secondary MX is the CSNET Relay (relay.cs.net and relay2.cs.net). They eventually destroyed over 11,000 copies of the error message in the queues on the two relay machines. Their post- mistress was at wit’s end when I spoke to her. She wanted to know what had hit her machines. It seems that for every one machine that had successfully contacted apple.com and delivered a copy of that error message, there were three hosts which couldn’t get ahold of apple.com because we were overloaded from all the mail, and so they contacted the CSNET Relay instead. I also heard from CSNET that UUNET, a major MX site for many other hosts, had destroyed 2,000 copies of the error message. I pre- sume that their modems were very busy delivering copies of the error message from outlying UUCP sites back to us at Apple Computer. This instantiation of this problem has abated for the moment, but I’m still spending a lot of time answering e-mail queries from postmas- ters all over the world. The next day, I replaced the current release of MAIL*LINK SMTP with a beta test version of their next release. It has not shown the header mangling bug, yet. The final chapter of this horror story has yet to be written. The versions of sendmail with this behavior are still out there on hun- dreds of thousands of computers, waiting for another chance to bury some unlucky site in error messages.
Apple Computer’s Mail Disaster of 1991 89 Are you next? [insert theme from “The Twilight Zone”] just the vax, ma’am, Erik E. Fair fair@apple.com