Server Fault is a question and answer site for system and network administrators. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

If the options in the mailman admin interface are set to "try to avoid duplicates" and every members is also set to "no duplicates", what are possible reasons if one of the subscribers receives each and every message twice?

Is it safe to say that it can't have anything to do with the list?

share|improve this question
up vote 0 down vote accepted

Ask said subscriber to send you all the headers for both messages. You should be able to tell the difference between them - it's possible that something along the way duplicated them, but the timestamps on headers normally makes it obvious.

share|improve this answer
Thanks, I asked them to send the headers. – Olaf Apr 13 '11 at 15:32

If this is happening to just one subscriber, I would say the likelihood is that they are either subscribed twice with two addresses that go to the same mailbox, or their mail server is doing something funny.

share|improve this answer
Thanks for the confirmation! – Olaf Apr 13 '11 at 15:31

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.