[Mailman-Users] Messages discarded by ISP

The obvious one is
Precedence: list

But that's a silly thing to filter on, and it is correct for Mailman to
insert it.

They might not like
From: <your address with them> coming with the envelope sender.

Or they might be running a silly challenge-response system

All of those would essentially mean that one can't receive messages from
mailing lists at that ISP (or that you have to configure something related
to your account to allow it).

Anyone else?

--John

Presumably, Mailman is sending via the same Sendmail server.


And the envelope.


I just want to emphasize this. When you send via your mail client, the
message is From: you and the envelope is most likely from you, but
when you post to your list and Mailman sends, the message is still
From: you (assuming you don't have an anonymous list), but the
envelope is from <listname>-bounces at list.domain.

Your ISP may well decide that a message purportedly from you at your.isp
sent by some other domain is forged.

This is certainly possible, but I want to emphasize this: if the ISP is
doing this they are 100% WRONG!

RFC 2821 specifies that the envelope header "From" can -- and in some cases
MUST -- differ from the "From" in the message itself. There are a variety of
headers, such as From, Resent-From, Errors-To, and there are legitimate
reasons for all of them to be different.

If you find an ISP that is blocking mail from your list due to the makeup of
the envelope headers, you should encourage them to read the relevant mail
transport RFCs and invest in some decent Bayesian spam filtering software.
Then encourage your subscribers at that ISP to find another ISP

Thank you very much John & Mark for your answers!

I don't know if it is related to Mailman-Users but... is there some way to change the envelope of the messages?

Bye,

Antonio

There is no "setting" for this. You have to change the code in
Mailman/Handlers/SendMail.py, but if you do, it will break automated
bounce processing.

Thanks Mark!
I prefer to "break" automated bounce processing instead of letting my
subscribers without their "e-news" paper? ;)

In the other hand, I have read some recommendations about not to use
Sendmail.py and I imagine Mailman is not using it because I have not
changed the default configuration (am I wrong?)
Anyway, I'm away from my office until Monday and I can't take a look
on the configuration files remotely.

Regards,
Antonio

My mistake. You are not using Sendmail.py (you have to do several,
non-default things to enable it and make it useable). I was typing too
quickly and carelessly. I meant Mailman/Handlers/SMTPDirect.py, not
Sendmail.py.

However, I think you said that your problem, if it is caused by the
envelope sender, is limited to recipients in your own ISP's domain.
Perhaps you could 'fix' it in some other way. I think you first need
to determine, perhaps with the ISP, exactly why these messages aren't
being delivered. Since your Sendmail MTA reports no error, it somehow
is occurring within the ISP. If it is the fact that the From: is from
a user in the ISP's domain, and the envelope is not, it would seem to
say that no one could post to any Mailman (or perhaps other MLM) list
from that domain and have their post delivered back to anyone in that
domain. It doesn't seem that the ISP would really want that.

One thing I would test is to send a message from one of the other
addresses on the list (say the gmail account) and see if the message
makes it to all of the recipients.

I had a problem that sounds a lot like yours. The cause was the ISP
filtering out incoming messages with a from address with their domain
name. If someone from a different domain sent a message, it all worked
fine.

If that is the cause of your problem, I have a custom handler that I
could probably clean up and send to you that would get you most of the
way to fixing the issue.

An even simpler fix is to make the list anonymous but that has it's own
list of drawbacks.

Good luck!

-Matt

Thank you very much to all!
I have solved the problem with your guidance?

After reading the last messages from Mark, Peter and Matt, I decided
to dig into the "list address affair (the sender header)"? for my
surprise, the email sender was "listname-bounces[at]myhostname"
instead of "listname-bounces[at]myhostname.domain_name", after
changing the option "host_name" in "General Options" to a full
qualified domain name, the problem was solved!

My ISP was discarding the messages because the sender was not
formatted properly... not a "legal" name for their SPAM filters I
think.

Regards!

Antonio

Antonio Dragone sent the message below at 14:31 5/22/2006:
---------------- End original message. ---------------------

It probably has nothing to do with spam filters.
If your ISP has their MTA properly configured so
it is not an open relay, it is very likely the
MTA refusing to relay mail from a source it does
not recognize as valid. Without the fully
qualified domain name, the MTA has no idea if
somebody is trying to bounce spam off of it, it
needs it to verify that the mail is from an allowed sender.

This is a good thing.

Dragon

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