DMARC munge action breaks CC: header with full personalization

Bug #1312970 reported by Robert Mathews on 2014-04-25
6
This bug affects 1 person
Affects Status Importance Assigned to Milestone
GNU Mailman
Medium
Mark Sapiro

Bug Description

If you use full personalization, the resulting headers on a message usually look like:

From: Sender <email address hidden>
To: Recipient <email address hidden>
Cc: <email address hidden>

Note the "Cc:" (added by Mailman/Handlers/CookHeaders.py beginning at line 191). The presence of the Cc: header makes "Reply to All" and "Reply to List" appear in many mail clients.

If a DMARC munge happens, Mailman/HandlersModerate.py does this at line 61:

msgdata['from_is_list'] = 1

However, CookHeaders.py at line 202 later notices that and fails to add the Cc: header because of it.

Because of this, the headers of a munged message, for example, will look like:

From: Sender via list <email address hidden>
Reply-To: Sender <email address hidden>
To: Recipient <email address hidden>

There is no "Cc:" header present at all, and popular clients like Gmail don't offer recipients a "Reply to All" choice for DMARC-munged messages.

It seems that when using full personalization, the Cc: header should appear whether or not the From and Reply-To were munged due to DMARC.

(I have manually verified that if the Cc: header was present -- that is, if the munged headers looked like this:

From: Sender via list <email address hidden>
Reply-To: Sender <email address hidden>
To: Recipient <email address hidden>
Cc: <email address hidden>

... then Gmail would correctly offer both "Reply" and "Reply to All" options and send them to the right places.)

Related branches

Revision history for this message
Mark Sapiro (msapiro) wrote :

Thanks for your report and detailed analysis. I'll fix it soon.

Actually, the Cc: has nothing to do with 'reply to list'. That's based on the RFC 2369 List- headers, but I see the issue if the list address is only in From: which is superceded by Reply-To:

Changed in mailman:
assignee: nobody → Mark Sapiro (msapiro)
importance: Undecided → Medium
milestone: none → 2.1.18rc3
status: New → In Progress
Revision history for this message
Robert Mathews (rob-launchpad-net) wrote :

> Actually, the Cc: has nothing to do with 'reply to list'

Of course you're right -- my mistake. This only affects "Reply to All".

Mark Sapiro (msapiro) on 2014-04-26
Changed in mailman:
status: In Progress → Fix Released
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