Comment 1 for bug 1604181

When you say you get 3 addresses, do you mean all 3 addresses are in Reply-To: or do you mean that when you 'reply' in your MUA (and what is that?) the reply is addressed to those 3 addresses.

It sounds as if you may have set from_is_list to Munge From for this list., but I'm not sure. I've never seen anything like <email address hidden> being put in Reply-To: by Mailman. Possibly the original post had Reply-Tp: poster (i.e. poster without a domain and your MTA rewrote the unqualified address by adding your domain.

If from_is_list to Munge From, a message from the list with first_strip_reply_to = Yes, reply_goes_to_list = This list and Mailman 2.1.16 that was sent To: <email address hidden> From: <email address hidden> should have headers

From: bob via list <email address hidden>
Reply-To: <email address hidden>, <email address hidden> plus anything else in Bob's original Reply-To:

The current release is similar except <email address hidden> will be added to Cc: rather than Reply-To:

There have been ongoing changes in this area in almost every release since 2.1.16, but without understanding more about exactly what you are seeing, I can't say if this is something that's been 'fixed' or a bug or intended behavior.

See http://bazaar.launchpad.net/~mailman-coders/mailman/2.1/view/head:/NEWS for all the changes since 2.1.16.