On 10/20/2015 04:45 PM, Marco Stoecker wrote:
I see a pattern now, when duplicates occur and it may have to do with mailman. If someone in a list send an email to two or three lists on the same server, the recipients of the list will get two or three times the same email. If it is sent to one list only, no duplicate occur. Any glue what the root cause could be?
If you are saying that people who are members of more than one list receive a copy from each list of which they are a member when a post is sent to multiple lists, that's the way Mailman works.
I.e. If I am a member of list1, list2 and list3 and someone posts to all three lists, I will receive a copy from each list.
The list member setting "Avoid duplicate copies of messages?" (nodupes) does not affect this. It only affects whether I receive a list copy if I am also a To: or Cc: addressee of the post.
The list's Non-digest options -> regular_exclude_lists can modify this behavior somewhat. E.g., if the regular_exclude_lists setting for list1@example.com includes list2@example.com and list3@example.com and the regular_exclude_lists setting for list2@example.com includes list3@example.com, then a member of all three lists will receive a copy of a post sent to all three lists from only list3@example.com.
regular_exclude_lists need to be set up with care. In particular, if list2@example.com is in list1@example.com's regular_exclude_lists, list1@example.com MUST not be in list2@example.com's regular_exclude_lists or a post sent to both lists will not be received by anyone who is a member of both lists.
Note that in the above, member means non-digest member. Digest members are not affected by this.