Beader Hobo Error Message
SMTP error from remote mailer after end of data: host FORT-POINT-STATION.mit.edu [188.8.131.52]: 553 beader hobo
All it means is that the message-id didn't pass muster with the slightly pedantic MIT sendmail configuration. Probably it needs an "@" sign or surrounding brackets. A message id is supposed to be a syntactically valid email address in brackets. The mysterious message is a little joke, a corruption of "header boho".
There is also the similar "bender sobo" if you have an invalid sender address.
The programmer seems to have felt that these messages would be seen only by spammers, so that plain language would be wasted.
feenberg isat nber dotte org