--> Jason LaMar wrote: --> >We have a fairly large list (more than 26,000 subscribers), and recently it --> >appears a very small fraction of the subscribers have started receiving --> >duplicate messages -- sometimes as many as a dozen or more. This behavior --> >just started happening within the last couple of weeks, and it seems to only --> >impact a minute and random subset of the subscribers. Anyone seen similar --> >behavior or have suggestions on the most effective way to troubleshoot this? --> --> There have been a number of discussions regarding similar things in --> the last few months. IIRC almost all of them were due to filter rules --> on the receiver end. --> --> A search of the list archives for "duplicate posts" or something --> similar ought to turn up the discussions. I don't know if anything --> exists in the FAQ regarding this. However, it is highly unlikely that --> Mailman is the culprit here. A check of the Mailman SMTP log and MTA --> logs should be able to determine if multiple copies are being sent. --> --> Far more likely is that the subscribers are getting multiple copies --> of replies to their posts or they have filter rules that are copying --> the posts instead of moving them.
I also suggest checking whether the subscribers receiving multiple copies use the same ISP (or the same small set of ISPs). I have seen several ISPs who install "upgrades" to their MTAs and cause this symptom. One of the root causes has been receiving MTAs that terminate the MTA-to-MTA TCP connection before the SMTP final acknowledgement has been processed; this causes a properly behaving sending MTA to believe that the message handoff was not* successful, and retransmit. If you can get the users to forward you the duplicate messages, with complete mail headers, you can sometimes spot this behavior in the "Received:" fields. For example, if the ISP has multiple mail exchangers ("nslookup -query=mx userisp.domain"), the duplicate copies may come through different mail exchangers in close time sequence, as the sending MTA tries one mail exchanger after the other. Beau --> >We're running version 2.1.5 on Red Hat Linux ES, and we've also had a few --> >runaway Python processes in the last couple of months that forced us to --> >restart the server. Perhaps this is all related and we just need to upgrade --> >to 2.1.9. Anybody happen to have a pre-built RPM for RHEL 4 with the latest --> >release? --> --> Are you committed to Red Hat's way of doing things? If you don't --> really care about their file hierarchy system, I would suggest --> dumping the RPM and compiling from source yourself. I've done a --> source install of various versions of Mailman on both an RHEL 4 and --> an RHEL 6 system and never had a problem with doing so. --> --> Otherwise, you are pretty much doomed to being behind a bit on --> releases if you rely on a package distribution of Mailman. --> --> Dragon --> --> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ --> Venimus, Saltavimus, Bibimus (et naribus canium capti sumus) --> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ --> --> ------------------------------------------------------ --> Mailman-Users mailing list --> Mailman-Users@python.org --> http://mail.python.org/mailman/listinfo/mailman-users --> Mailman FAQ: http://www.python.org/cgi-bin/faqw-mm.py --> Searchable Archives: http://www.mail-archive.com/mailman-users%40python.org/ --> Unsubscribe: http://mail.python.org/mailman/options/mailman-users/bjames%40cisco.com --> --> Security Policy: http://www.python.org/cgi-bin/faqw-mm.py?req=show&file=faq01.027.htp --> ------------------------------------------------------ Mailman-Users mailing list Mailman-Users@python.org http://mail.python.org/mailman/listinfo/mailman-users Mailman FAQ: http://www.python.org/cgi-bin/faqw-mm.py Searchable Archives: http://www.mail-archive.com/mailman-users%40python.org/ Unsubscribe: http://mail.python.org/mailman/options/mailman-users/archive%40jab.org Security Policy: http://www.python.org/cgi-bin/faqw-mm.py?req=show&file=faq01.027.htp