On Wed, 6 Mar 2019, Hélio Guilherme wrote: Sorry about that. It's actually nothing to do with moving the mailing list to Ancona (which we need to do before long, but that's another story). It's now the second time that a bunch of gmail users have been automatically unsubscribed from the list, due to some bug in the relationship between gmail and mailman. Gerhard Gonter (who was affected the first time this happened) wrote to me: <quote> I just had the same problem for one of my own mailman lists. The original poster sent from Gmail, hence the mail had a DKIM signature which mailman did not remove when it was distributed. The mail was rejected for all of my gmail subscribers. The exim log for my address had this message: --- 8< --- 2019-02-13 12:43:51 1gtsx6-0003hA-CK ** ggonter(a)gmail.com R=dnslookup T=remote_smtp: SMTP error from remote mail server after end of data: host gmail-smtp-in.l.google.com [64.233.167.27]: 550-5.7.1 This message does not have authentication information or fails to pass\n550-5.7.1 authentication checks. To best protect our users from spam, the\n550-5.7.1 message has been blocked. Please visit\n550-5.7.1 https://support.google.com/mail/answer/81126#authentication for more\n550 5.7.1 information. w7si11160169wrt.101 - gsmtp --- >8 --- I guess I need to filter DKIM signatures or do something else. </quote> I'm not sure where this leaves us, but it's a serious bother. Allin