I just wanted to close this old topic with a thanks to Bryan Carbonnell (and anyone else) who successfully diagnosed the issue of mail duplication as mis-configured Outlook rules rather than a problem with mailman processing CC, reply-to, etc..
Thanks to anyone who responded. I'll go flog myself once for every person who's time has been wasted here. :) Tony
Bryan Carbonnell wrote:
Just to recap the details as I recall them
- You are the only one seeing the duplicate e-mails
- You are using Outlook.
- Duplicate e-mails are idendical down to the header level.
- Only happens on 1 list.
- Only happens when the list is in the CC header.
If all the above are correct, check your Outlook rules. Outlook may be the cause of the duplicates.
I've spent a TON of time trying to diagnose this for one user and it turned out it was her Outlook rules that caused the duplicate.
I don't use Outlook myself, but try disabling the rule for a while and see if the duplicates still happen. If not, then recreate the rule.
I know this isn't Mailman related, but I think that this may be a good cause for the archive.