[Mailman-Users] From Header Changed

Mark Sapiro mark at msapiro.net
Sun Feb 24 21:01:29 CET 2013

Mark Sapiro wrote:

> On 2/13/2013 6:11 AM, Dennis Putnam wrote:
>> I have not made any changes (intentionally) to mailman in many months
>> but suddenly mail from the list has listname-bounces as the from header
>> rather then the original poster.

It turns out that the OP is using a Yahoo server as a smarthost to relay
Mailman's mail. It is Yahoo that is rewriting the From: header.

I finally did some experimentation with sending via a Yahoo server. This
is what I found

I connect to smtp.mail.yahoo.com:465 (SSL) and authenticate with my
Yahoo address.

I issue a MAIL FROM. If the address is not a verified address on my
Yahoo account, the MAIL FROM is rejected with '553 From address not
verified - see
(note, this URL doesn't exist, but other help indicates you have to send
from addresses which are verified for your account. It seems the OP has
realized this and has verified the listname-bounces address on his Yahoo
account so Mailman's mail will be accepted.

If the address is verified, I can proceed and send the mail. The result
depends on whether the From: address in the mail is or is not a verified
address on my Yahoo account.

If the From: is a verified address, the From: header is not rewritten,
but the envelope sender address is rewritten to the From: header
address. In the case of Mailman, this will break bounce processing as
bounces will return to the poster and not to Mailman.

If the From: is not a verified address, the entire From: is replaced
with one containing only the verified envelope sender address, i.e., the
listname-bounces address in the Mailman case. This is what is apparently
happening in the OP's case and appears to be a change at Yahoo.

The implication of this is that Yahoo is simply not viable as a
smarthost relay for Mailman's outgoing mail.

Note that Gmail/googlemail is not a viable alternative either as
Gmail/googlemail always rewrites both the envelope sender address and
the From: header address to the Gmail/googlemail address used to
authenticate to the server. Gmail/googlemail at least leaves the
original display name in the From: header, but that's all.

>> Also, I'm guessing this is related, bounced messages are now being
>> handled as uncaught bounces.
>> The attached message was received as a bounce, but either the bounce
>> format was not recognized, or no member addresses could be extracted
>> from it.  This mailing list has been configured to send all
>> unrecognized bounce messages to the list administrator(s).

This turned out to be a bounce format from Yahoo that wasn't recognized
by Mailman. The recognizer will be updated for this.

Mark Sapiro <mark at msapiro.net>        The highway is for gamblers,
San Francisco Bay Area, California    better use your sense - B. Dylan

More information about the Mailman-Users mailing list