Just a quick pointer to an article in German for those 350+ Subscribers with a t-online-Mailaddress.

T-Online verbessert den Spamschutz - Legitime Mails werden abgelehnt.

Summary: T-Online now blocks non-spam Mail from Debians Listserver.

T-Online hat seinen "Plattformschutz optimiert" und nimmt nun "offensichtlich unerwünschte E-Mails (SPAM, UCE, UBE, Phishing)" nicht mehr an, noch bevor sie den Spam-Filter erreichen.

(Aus: http://www.golem.de/0803/58682.html)

und wir haben gleich den ersten Treffer:

http://lists.debian.org/debian-user-ger ... 01875.html

wurde von den neuen verbesserten Filter als Spam abgelehnt:

<*deleted*@t-online.de>: host mx03.t-online.de[194.25.134.73] said: 550
5.7.0 Message considered as spam or virus, rejected (in reply to end of
DATA command)

--A45C013A4E6D.1206832310/liszt.debian.org
Content-Description: Delivery report
Content-Type: message/delivery-status

Reporting-MTA: dns; liszt.debian.org
X-Postfix-Queue-ID: A45C013A4E6D
X-Postfix-Sender: rfc822; bounce-debian-user-german@lists.debian.org
Arrival-Date: Sat, 29 Mar 2008 23:06:17 +0000 (UTC)

Final-Recipient: rfc822; *deleted*@t-online.de
Action: failed
Status: 5.7.0
Remote-MTA: dns; mx03.t-online.de
Diagnostic-Code: smtp; 550 5.7.0 Message considered as spam or virus, rejected

... because they are bouncing.

In my ongoing attempt to investigate and fix problems of our mailinglist-server, i found that we only had a working bounce-detection for lists starting debian-* minus debian-private and the three digest-lists.

So i rewrote some parts of the bounce detection:

We now have four categories of lists:

• high (30 or more mails a day)
• medium (20 or more mails a week)
• low (10 or more mails a month)
• very-low (the rest)

for these four categories we calculate a spam-rate depending on the number of distributed messages and the number of bounces in the timerange of 24 hours for 'high' lists, 7 days for 'medium' lists, 30 days for 'low' lists and 90 days for 'very-low' lists.

If the Spamrate exceeds 80% for unmoderated, and 60% for moderated lists, and bounces have been seen for more than 24 hours we kick. (these rates are subject to change, when we have implemented the warning mechanism)

So these changes implemented a bounce-detection for debian-changes-digest and today we reached the level of 60% bounces for more than 500 subscribers.

So what next?

To finish the bounce-detection, i want to implement something which tries to notify subscribers about bouncing mails. This is useless for 'hard'-bouncers, but people with some smaller problems like mail2news-gatewayers this could be helpful. I also want to implement something which sends out unsubscription notices for three weeks after the kick, so kicked out people can resubscribe after they have sorted out the problems.

Both should fire once a week per address.

What do you think?

While analysing the pole setters in our internal bouncers-Hitlist i found that some of them run a mail2news-Gateway.

The problem is: our Mailinglists leave Mail-Headers mostly untouched, and so headers like X-Trace or X-Complaints-To are passed through without modifications.

If a mail containing those headers is handed over to inews (as in INN) it rejects it, and the bounce comes back to us:

<XXXXX@XXX.com>: Command died with status 1: "/usr/bin/maildrop". Command
output: inews: cannot send article to server: 441 Can't set system
"X-Complaints-To" header inews: article not posted

so people: fix your systems. if you do more with listmail than dropping it somewhere make sure that the bounces your system produces go to someone who can fix it. We (as in listmasters) normally simply unsubscribe those.

btw: we talk about 18181 bounces since 08.2004 in this case.

Just a quick note:

while wading through the list-archives, drop-boxes and list-configuration to find false positives and possiblities to optimise our mailinglists spam level i accidently removed the inclusion of our spamfilters from most lists.

I appologise for this.

Luckily zobel discovered my error and fixed it at 14:30 CET.