They are sending spam bounce messages based on spamassassin testing this list.
===8<--- This message was created automatically by mail delivery software. A message that you sent could not be delivered to one or more of its recipients. This is a permanent error. The following address(es) failed: users@spamassassin.apache.org SMTP error from remote mailer after end of data: host asf.osuosl.org [140.211.166.49]: 552 spam score (11.5) exceeded threshold ===8<--- That is VERY improper behavior. 1 - sending the bounces makes you a joe-job site, 2 - people who antispam test this list are too dumb to live on the list. Putting the two together exceeds my "give them a break" level. {^_^}