Hi Mailman developers,

we at freexp.de are setting up Mailman and INN and are trying to get the Mail<->News facility to work. We are neither familiar with Mailman nor with Python, just being poor old Pascal programmers. ;)

I have been in touch with Brad Knowles before and he advised me to ask here.

We have three mailing lists and three corresponding newsgroups, which shall be gated bidirectional. It even works but what is puzzling us is that in Mail->News direction Mailman always creates an own MsgID. This screws up threading by references: If a newsgroup user replies to a posting that has been gated from the mailing list to the newsgroup, then

• from the perspective of the mailing list users - his references point to a "wrong" MsgID when they receive this followup posting being gated from the newsgroup to the mailing list.

I found the respective code in Queue/NewsRunner.py and also read the explanation why Mailmain is creating own MsgIDs (I'll come back to this later on). I changed the code as follows:

----------8<---------- # Our Message-ID format is <mailman.secs.pid.listname@hostname> msgid = msg['message-id'] hackmsgid = True if msgid: hackmsgid = False # mo = mcre.search(msgid) # if mo: # lname, hname = mo.group('listname', 'hostname') # if lname == mlist.internal_name() and hname == mlist.host_name: # hackmsgid = False if hackmsgid: del msg['message-id'] msg['Message-ID'] = Utils.unique_message_id(mlist) ----------8<----------

It is not really clear to me how Python can know where a conditional statement such as "if msgid:" ends (just by the indention?), but this piece seems to work: The MsgID is now being left untouched.

This is question #1: Is this code OK? I'm also not sure if the variable 'msgid' contains a boolean or a string...?

Now to the more important issues:

I understand that there are two main reasons why Mailman wants to create an own MsgID upon gating Mail->News, one of them being to avoid loops.

Even after I changed the code as above, I still can't see a loop. I first thought Mailman might check the MsgID of a posting upon deciding whether it should be gated from the newsgroup to the mailing list, but this is obviously not the case. I've had a look into cron/gate_news.py but couldn't figure out exactly how Mailman is taking that decision.

This is question #2: How does Mailman know if the mailing list has already seen a posting or not?

Anyway, the second and more important reason for creating own MsgIDs seems to be the issue of an XPost to two (or more) Usenet-gated mailing lists.

This is indeed a problem and I understand the background. Thus we'd like to tweak Mailman in a way that it does the following:

1. Say we have the mailing lists ml-1, ml-2 and ml-3 and the corresponding newsgroups ng-1, ng-2 and ng-3. Now a mail comes in, being addressed to ml-1 and ml-2 (which thus should be gated to ng-1 and ng-2).

   In fact, two physical mails will come in, and obviously Mailman does now create two physical postings, one addressed to ng-1, the other one addressed to ng-2. This in fact creates the problem of duplicate MsgIDs.

   But what Mailman should do is to create *one* physical posting, x-posted to ng-1 and ng-2 ("Newsgroups: ng-1,ng-2"). This would mean that upon dealing with the mail to ml-1 it would have to check if the addresses in the To: and Cc: headers contain more than one of "our" mailing lists and if these mailing lists are being gated to "our" Newsgroups. If so, then an x-posting as described shall be created.

   When Mailman now has to deal with the second mail to ml-2 (with the same MsgID) it shall *not* create another posting anymore.

   Can this be accomplished (and if yes, how)?

2. Of course, if a mail does not have a MsgID at all, then Mailman should still create its own MsgID.

Any hint will be appreciated (and again, please consider that we are newbees with regards to Mailman and Python). Even if we would have to hardcode some strings (of mailing lists and/or newsgroups) this would be a better solution than no solution.

    Michael