[Mailman-Users] Mailman integration with Google Groups:allowGroups Subscribers post directly

anatoly techtonik techtonik at gmail.com
Sun Apr 17 09:26:34 CEST 2011

On Sat, Apr 16, 2011 at 10:01 PM, Mark Sapiro <mark at msapiro.net> wrote:
> anatoly techtonik wrote:
>>On Tue, Mar 29, 2011 at 9:49 AM, Mark Sapiro <mark at msapiro.net> wrote:
>>> anatoly techtonik wrote:
>>>>- how can I setup Mailman, so it can accept mails sent through Google
>>>>Groups proxy automatically? -
>>> The envelope sender of a google groups post is
>>> <group_name+some_token at googlegroups.com>. If that address were a
>>> member of the mailman list with no password reminders and no mail
>>> delivery, the posts would be accepted as member posts. The problem is
>>> the +some_token suffix to the local part of the address. The
>>> Mailman.Message.get_senders() method doesn't treat +some_token as a
>>> suffix and since it is variable, it is not possible to subscribe all
>>> the possible<group_name+some_token at googlegroups.com> addresses to the
>>> list.

Let me concentrate on this part once more. I need only one group to be
a frontend for one list. So I need only mails from this group to be
delivered - not from all groups. If I understood correctly,
+some_token is regenerated every post and it is "envelope address". My
own @gmail.com address it not seen by Mailman when the message
arrives, so the From: format is "My Name
<group_name+some_token at googlegroups.com>". Is this right?

I am not an administrator and can't validate this information. Just to
make clear about the situation. The problem with just subscribing
group address that when I post through the group (not being subscribed
to the list), my post seems to appear in group only, but not on
mailing list. I don't receive any notifications or bounces. But when I
subscribe to the list, my post seem to pass through.

>>Is it possible to add an option to Mailman itself to strip +token
>>before processing email addresses?
> Only by modifying code.

Does it qualify as a feature request?

>>Does email standard allow to use +token addresses for multiple users?
> I do not understand the question. There will be one message from the
> Google Group to the Mailman list. That message's envelope sender will
> have a unique token so if it bounces, Google can easily tell which
> recipient bounced. The messages from the Google Group to other Google
> Group members will each have their own unique token.

I see. I thought that if +token is something optional and that email
standard specifies that "email+something at domain.com" is equivalent to
"email at domain.com" and denotes the same recipient, and that email
agents are not required to process the +part, then Mailman could just
ignore it.

>>> Thus you are left with a couple of other options. If the Google group
>>> is set to include a Reply-To: <group_name at googlegroups.com> header in
>>> delivered posts, and if <group_name at googlegroups.com> is a member of
>>> the mailman list (with no password reminders and no mail delivery),
>>> Mailman.Message.get_senders() will return that address in the senders
>>> list and Mailman will consider the post from a member.

The group is set into "Replies are sent to the whole group." mode. But
the subscribed address is <group_name+token at googlegroups.com>. Now I
see where the problem is.

>>I'd like to ensure there is some kind protection to
>>avoid spam that pretends to be from the Group. The same concern is
>>about X-BeenThere header solution.
> It doesn't take much sophistication to craft and send an email message
> with anything one wants in the headers. People who want to can already
> easily spoof the address of any list member in the From: header of a
> message to fool Mailman into accepting the post as from a list member.

I thought there is a reverse MX check to validate the message was sent
from the IP that belongs to MX record for this domain.

>>> So, if you add <group_name at googlegroups.com> as a member of the mailman
>>> list (with no password reminders and no mail delivery), and either set
>>> the google group "Replies to messages" =C2=A0to "Replies are sent to the
>>> whole group" or add the above SENDER_HEADERS line to mm_cfg.py, posts
>>> arriving via the group will be seen as member posts.
>>If I set "no mail delivery" then how the Group receive messages for
>>reading from the web?
> No mail delivery is a per user option. You set no mail delivery and no
> password reminders for only the Google Groups address which is a
> member of the Mailman list so that Mailman doesn't send the post back
> to the Google Group. Delivery to other members of the Mailman list is
> unaffected by this.

Still can't understand how Google Group receive messages if Mailman
doesn't send anything to its address. Do you mean that "no mail
delivery" means that Mailman still sends all messages to Groups
address except messages that were posted from this group (containing
Group address in Reply-To: header)?

anatoly t.

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