On Mon, Jun 05 2023, Mark Sapiro wrote:

Changes like those above are due to Python's stdlib email module.

Ok, I'll submit a bug report.

Instead, you should be DKIM signing your outgoing mail and perhaps applying Mailman's DMARC mitigations if DMARC is an issue.

I would like to keep things as simple as possible.

Before changing my setup, I'll see, if there is any chance, that the email module gets fixed.

-- Peter

On 6/5/23 10:07, Peter Münster wrote:

On Mon, Jun 05 2023, Mark Sapiro wrote:

...

Changes like those above are due to Python's stdlib email module.

Could you point me to the code please, where the module is called?

Basically, all over.

https://gitlab.com/mailman/mailman/-/blob/master/src/mailman/email/message.p... defines a mailman.email.message.Message class which is a subclass of Python's email.message.Message class.

https://gitlab.com/mailman/mailman/-/blob/master/src/mailman/runners/lmtp.py... makes a mailman.email.message.Message object from the incoming bytes. This object is passed around through many Mailman modules and ultimately https://gitlab.com/mailman/mailman/-/blob/master/src/mailman/runners/outgoin... calls the delivery function which has multiple paths which all wind up at https://gitlab.com/mailman/mailman/-/blob/master/src/mailman/mta/connection.... to send the message. and current code (Mailman >=3.3.6) will actually pass the message object to Python's smtplib <https://docs.python.org/3/library/smtplib.html#smtplib.SMTP.send_message> to send it.

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

On 6/5/23 14:59, Peter Münster wrote:

On Mon, Jun 05 2023, Mark Sapiro wrote:

...

Basically, all over.

Thanks. I would like to find out, which function is responsible for the modification of the body, before filling a bug report. Unfortunately I don't have any experience with Python, so any help is highly appreciated. My idea is to add "print(message)" at the places, that you mentioned. Where would I find the output then?

You don't want to use print statements. All those modules do logging to various logs so they pretty much all import logging. Then you add something like

dlog = logging.getLogger('mailman.debug')

near the beginning of the module and then add things like

     dlog.info(msg.as_bytes())

to write the message to debug.log.

However, I would not proceed in that way. I would start by putting the raw problem message as it comes to mailman in a file and then use mailman shell do to things like

 >>> import email
 >>> import smtplib
 >>> from mailman.email.message import Message
 >>> with open('path/to/message/file', 'rb') as fp:
...     msg = email.message_from_binary_file(fp, Message)
...
 >>>

to create the message object, and then do something like

 >>> conn = smtplib.SMTP()
 >>> conn.sendmail(from_addr, to_addrs, msg)

to send the message to to_address and see if it has the added lines. Or maybe just

 >>> print(msg.as_bytes())

to see if that has the added lines. It may be necessary to do things like

 >>> msg['Message-ID-Hash'] = 'aaaaa'

to add a header to create the issue.

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

On Tue, Jun 06 2023, Peter Münster wrote:

I can send a bug report!

Oh, someone else has already done that: https://github.com/python/cpython/issues/105333

-- Peter