mails relayed from lists.tpo to gmail.com bounces
It seems we're having trouble relaying mails to gmail.com and possibly other providers.
A similar question was raised by a tor-announce@ participant in
I myself had trouble sending mail to a @tpo account that is forwarded to gmail (bounce is
<firstname.lastname@example.org>: host gmail-smtp-in.l.google.com[18.104.22.168] said: 550-5.7.1 This message does not have authentication information or fails to pass 550-5.7.1 authentication checks. To best protect our users from spam, the 550-5.7.1 message has been blocked. Please visit 550-5.7.1 https://support.google.com/mail/answer/81126#authentication for more 550 5.7.1 information. f2si4120705wrj.403 - gsmtp (in reply to end of DATA command)
I suspect this might have to do with (lack of) SPF records and/or ARC headers.