I was dropped from the list earlier this week - our campus HelpDesk has since gotten other faculty reporting that they are being dropped from listservs with similar error messages.
- The last reported error was: 5.7.1 550-5.7.1
[2600:3c03::f03c:91ff:fe55:a961] Our system has detected that this
550-5.7.1 message does not meet IPv6 sending guidelines regarding PTR
records 550-5.7.1 and authentication. Please review 550-5.7.1
https://support.google.com/mail/?p=IPv6AuthError for more information 550
5.7.1 . r30... (25 bytes suppressed)
Please do not ignore this message. While you can re-subscribe to the list, it is important for you to report this problem to your mail administrator so that it can be solved. This problem is not specific to the CODE4LIB list and may also affect your private mail. This means that you may have lost some private mail as well. Anyone trying to write to you during the same time frame might have received the same errors for the same reason.