Duplicate emails being received
![](https://secure.gravatar.com/avatar/6b50c17f55d7174b281928faf6e87a4d.jpg?s=120&d=mm&r=g)
Hi,
I've got a list with ~1600 subscribers (Mailman 2.1.39). It gets one or two messages posted to it each day (by subscribers).
The problem: subscribers are all receiving duplicate copies of the original post and any replies.
All the subscribers are have "nodupes" switched on, and the list is set to replies to go to "This list".
I restarted the qrunner with: bin/mailmanctl -s restart
That seemed to resolve things for a moment but then it started up again.
Does anyone have any tips or pointers?
Cheers.
![](https://secure.gravatar.com/avatar/56f108518d7ee2544412cc80978e3182.jpg?s=120&d=mm&r=g)
On 10/17/22 16:25, Mark Dale via Mailman-Users wrote:
Are you saying that each list member receives 2 copies of an original post addressed only to the list?
All the subscribers are have "nodupes" switched on, and the list is set to replies to go to "This list".
That wouldn't be relevant for an original post addressed only to the list, nor would it be relevant for any user not directly addressed in To: or Cc: of the post.
Ensure you don't have multiple runners processing the same slice of their queues. See https://wiki.list.org/x/4030715 for the procedure to stop ALL Mailman processes and then start it only once.
Examine the Received: headers of both copies to determine the paths that the message takes from poster to recipient.
-- Mark Sapiro <mark@msapiro.net> The highway is for gamblers, San Francisco Bay Area, California better use your sense - B. Dylan
![](https://secure.gravatar.com/avatar/6b50c17f55d7174b281928faf6e87a4d.jpg?s=120&d=mm&r=g)
The problem: subscribers are all receiving duplicate copies of the original post and any replies.
Are you saying that each list member receives 2 copies of an original post addressed only to the list?
Each and every list member receives 2 copies of the post. It is addressed to the list AND CCed to the poster's own email address.
EG. FROM: Me via listname@listdomain.com TO: listname@listdomain.com CC: me@mydomain.com
Ensure you don't have multiple runners processing the same slice of their queues. See https://wiki.list.org/x/4030715 for the procedure to stop ALL Mailman processes and then start it only once.
I stepped through this (results below). After a reboot, there is only one runner.
/var/lib/mailman/bin/qrunner --runner=OutgoingRunner:0:1 -s
Examine the Received: headers of both copies to determine the paths that the message takes from poster to recipient.
I "diffed" the headers of both emails to check, and the message paths are the same.
After the reboot, I posted a test to the list(just the list address, no CC) and now just the one copy of the message is delivered (although it wrote my address into the CC field).
FROM: Me via listname@listdomain.com
TO: listname@listdomain.com
CC: me@mydomain.com
So far so good. I'll keep an eye on the qrunner over the next few days. It came good last time I restarted the qrunner, then went bad. But as you say, there may well have been more than one runner doing their bit.
Here are the steps and results I went through.
# service mailman stop
# ps -fAww |grep python root 432 1 0 Oct01 ? 00:48:57 /usr/bin/python3 /usr/bin/fail2ban-server -xf start nobody 5659 5658 0 00:25 ? 00:00:00 /usr/bin/python /usr/local/bin/mpanel-memory-graph root 5687 5642 0 00:26 pts/0 00:00:00 grep python ////// I SHOULD HAVE CHECKED THAT BEFORE STOPPING MAILMAN
# service mailman start /////// FAILED TO START ... Oct 18 00:30:12 syd systemd[1]: Starting Mailman Master Queue Runner... Oct 18 00:30:13 syd mailmanctl[5791]: Starting Mailman's master qrunner. Oct 18 00:30:13 syd systemd[1]: mailman.service: Can't open PID file /run/mailman/mailman.pid (yet?) after start: No such file or directory
/////// oh? MAYBE IT LIVES SOMEWHERE ELSE # find / -type f -iname "mailman.pid" /////// NO RESULT
///////// hmmm, AM I PANICKING YET? #reboot ///////// phew..., MAILMAN RUNNING AFTER REBOOT.
# pstree systemd─┬─agetty ├─cron .. ├─mailmanctl───python ├─master─┬─anvil │ ├─2*[bounce] ...
# ps -fAww |grep python ////////// LOOKS LIKE ONLY 1 RUNNER. So far, so good.
root 432 1 0 00:36 ? 00:00:00 /usr/bin/python3 /usr/bin/fail2ban-server -xf start list 745 1 0 00:38 ? 00:00:00 /usr/bin/python /usr/lib/mailman/bin/mailmanctl -s start list 751 745 2 00:38 ? 00:00:04 /usr/bin/python /var/lib/mailman/bin/qrunner --runner=OutgoingRunner:0:1 -s nobody 913 911 0 00:40 ? 00:00:00 /usr/bin/python /usr/local/bin/mpanel-memory-graph root 921 908 0 00:40 pts/0 00:00:00 grep python
/////// DID THAT PID FILE REAPPEAR? # find / -type f -iname "mailman.pid" /////// NO RESULT. ... shrug ...
All seems well, the list is delivering single copies of the message (for now).
Thank you Mark for that advice. Very much appreciated.
![](https://secure.gravatar.com/avatar/56f108518d7ee2544412cc80978e3182.jpg?s=120&d=mm&r=g)
On 10/17/22 18:43, Mark Dale via Mailman-Users wrote:
This is expected. See the comment in the code beginning at https://bazaar.launchpad.net/~mailman-coders/mailman/2.1/view/head:/Mailman/... for why we do this.
This is not unusual. It's not a concern.
There should be more. Where are ArchRunner, BounceRunner, CommandRunner, IncomingRunner, NewsRunner, VirginRunner and RetryRunner? Did you edit them out?
What does ps -fwwu list
show?
I suspect an issue with the Debian/Ubuntu package. What is the content of /etc/systemd/system/mailman.service?
All seems well, the list is delivering single copies of the message (for now).
Good.
-- Mark Sapiro <mark@msapiro.net> The highway is for gamblers, San Francisco Bay Area, California better use your sense - B. Dylan
![](https://secure.gravatar.com/avatar/6b50c17f55d7174b281928faf6e87a4d.jpg?s=120&d=mm&r=g)
On 2022-10-18 14:29, Mark Sapiro wrote:
Got it. Thank you.
I hadn't edited then out, but when I ran "ps -fAww |grep python" again just now, they're all present now. Good to know that all those are supposed to be there (in case there's a "next time"). And "ps -fwwu list" shows the same.
# ps -fAww |grep python root 432 1 0 00:36 ? 00:00:20 /usr/bin/python3 /usr/bin/fail2ban-server -xf start nobody 5348 5343 0 03:45 ? 00:00:00 /usr/bin/python /usr/local/bin/mpanel-memory-graph list 5407 1 0 03:47 ? 00:00:00 /usr/bin/python /usr/lib/mailman/bin/mailmanctl -s start list 5408 5407 0 03:47 ? 00:00:00 /usr/bin/python /var/lib/mailman/bin/qrunner --runner=ArchRunner:0:1 -s list 5409 5407 0 03:47 ? 00:00:00 /usr/bin/python /var/lib/mailman/bin/qrunner --runner=BounceRunner:0:1 -s list 5410 5407 0 03:47 ? 00:00:00 /usr/bin/python /var/lib/mailman/bin/qrunner --runner=CommandRunner:0:1 -s list 5411 5407 0 03:47 ? 00:00:00 /usr/bin/python /var/lib/mailman/bin/qrunner --runner=IncomingRunner:0:1 -s list 5412 5407 0 03:47 ? 00:00:00 /usr/bin/python /var/lib/mailman/bin/qrunner --runner=NewsRunner:0:1 -s list 5413 5407 0 03:47 ? 00:00:00 /usr/bin/python /var/lib/mailman/bin/qrunner --runner=OutgoingRunner:0:1 -s list 5414 5407 0 03:47 ? 00:00:00 /usr/bin/python /var/lib/mailman/bin/qrunner --runner=VirginRunner:0:1 -s list 5415 5407 1 03:47 ? 00:00:00 /usr/bin/python /var/lib/mailman/bin/qrunner --runner=RetryRunner:0:1 -s root 5422 5416 0 03:47 pts/0 00:00:00 grep python
# cd /etc/systemd/system/ # ls -la ... mailman-qrunner.service -> /lib/systemd/system/mailman.service
# cat /lib/systemd/system/mailman.service [Unit] Description=Mailman Master Queue Runner After=network.target
[Service] Type=forking PIDFile=/var/run/mailman/mailman.pid ExecStart=/usr/lib/mailman/bin/mailmanctl -s start ExecStop=/usr/lib/mailman/bin/mailmanctl stop ExecReload=/usr/lib/mailman/bin/mailmanctl restart Restart=always RestartSec=3s RestartPreventExitStatus=1
[Install] WantedBy=multi-user.target Alias=mailman-qrunner.service
It seems that it was looking for the PID file in "/run/mailman/mailman.pid" (below) and the above says it lives at "/var/run/mailman/mailman.pid"
Oct 18 00:30:13 syd systemd[1]: mailman.service: Can't open PID file /run/mailman/mailman.pid (yet?) after start: No such file or directory
![](https://secure.gravatar.com/avatar/56f108518d7ee2544412cc80978e3182.jpg?s=120&d=mm&r=g)
On 10/17/22 21:02, Mark Dale via Mailman-Users wrote:
Try changing that to
PIDFile=/var/lib/mailman/data/master-qrunner.pid
I'm only guessing where that is in the Debian package, but
locate master-qrunner.pid
should find it.
/var/run is typically a symlink to /run, but
https://mail.python.org/archives/list/mailman-users@python.org/message/OOVT7...
says you couldn't find a mailman.pid
anywhere.
Oct 18 00:30:13 syd systemd[1]: mailman.service: Can't open PID file /run/mailman/mailman.pid (yet?) after start: No such file or directory
-- Mark Sapiro <mark@msapiro.net> The highway is for gamblers, San Francisco Bay Area, California better use your sense - B. Dylan
![](https://secure.gravatar.com/avatar/6b50c17f55d7174b281928faf6e87a4d.jpg?s=120&d=mm&r=g)
On 2022-10-18 15:37, Mark Sapiro wrote:
Super! That did the job.
#PIDFile=/var/run/mailman/mailman.pid PIDFile=/var/lib/mailman/data/master-qrunner.pid ...
# service mailman stop Warning: The unit file, source configuration file or drop-ins of mailman.service changed on disk. Run 'systemctl daemon-reload' to reload units.
# systemctl daemon-reload # service mailman stop # service mailman start
# pstree ///////// MAILMAN RUNNING # ps -fwwu list ///////// ALL RUNNERS RUNNING
/var/run is typically a symlink to /run, but https://mail.python.org/archives/list/mailman-users@python.org/message/OOVT7... says you couldn't find a
mailman.pid
anywhere.
Yes. For "mailman.pid" nothing is found with either "find" or "locate".
For "master-qrunner.pid" -- no problem ...
# locate master-qrunner.pid /var/lib/mailman/data/master-qrunner.pid
# find / -type f -iname "master-qrunner.pid" /var/lib/mailman/data/master-qrunner.pid
![](https://secure.gravatar.com/avatar/baa72321ff7f0e9dd8a7ce2673cf7de6.jpg?s=120&d=mm&r=g)
On 10/17/22 5:25 PM, Mark Dale via Mailman-Users wrote:
Does anyone have any tips or pointers?
I've seen this type of duplication when there were communications problems that were causing your outbound MTA to send messages multiple times. This usually happens when there are communications problems and your sending MTA doesn't receive the confirmation from receiving MTAs that they have accepted the message. This might be a result of a timeout setting being too low on your sending MTA.
Given that your message to the mailman-users mailing list came to the list twice, which didn't involve your instance of Mailman, I sort of suspect you have lower level / SMTP problems.
I think that your MTA's logs will be a very good place to start looking. At least to see if there is evidence of problems or not.
-- Grant. . . . unix || die
![](https://secure.gravatar.com/avatar/6b50c17f55d7174b281928faf6e87a4d.jpg?s=120&d=mm&r=g)
On 2022-10-18 12:41, Grant Taylor via Mailman-Users wrote:
I've seen this type of duplication when there were communications problems that were causing your outbound MTA to send messages multiple times. This usually happens when there are communications problems and your sending MTA doesn't receive the confirmation from receiving MTAs that they have accepted the message. This might be a result of a timeout setting being too low on your sending MTA.
Thanks for that pointer.
At the moment the Postfix smtpd_timeout = 60s. I think the original default is 300s.
The restart (as per Mark S.'s advice) has got the mail back to one copy. If it goes off the rails again I'll experiment with that timeout.
Given that your message to the mailman-users mailing list came to the list twice, which didn't involve your instance of Mailman, I sort of suspect you have lower level / SMTP problems
That was my bad. I had a cert error and thinking the message hadn't been sent, I resent it. *</:-( (that's my dunce hat)
I think that your MTA's logs will be a very good place to start looking. At least to see if there is evidence of problems or not.
There is one timeout error (unrelated I think) that gets repeated every hour approx. for just one recipient.
Oct 17 18:31:47 syd postfix/smtpd[30094]: timeout after END-OF-MESSAGE from mpv-out-cfd-1.REDACTED-DOMAIN.COM[REDACTED-IP4-ADDRESS]
![](https://secure.gravatar.com/avatar/baa72321ff7f0e9dd8a7ce2673cf7de6.jpg?s=120&d=mm&r=g)
On 10/17/22 9:20 PM, Mark Dale via Mailman-Users wrote:
Thanks for that pointer.
You're welcome.
At the moment the Postfix smtpd_timeout = 60s. I think the original default is 300s.
I don't see any problem with having the higher value. Most connections will complete well within that amount of time. 20% of that time in fact. The few that don't will not adversely effect your server.
The restart (as per Mark S.'s advice) has got the mail back to one copy. If it goes off the rails again I'll experiment with that timeout.
ACK
Things happen.
There is one timeout error (unrelated I think) that gets repeated every hour approx. for just one recipient.
So you know what the error would look like and you have the absence of it as the source of the problem you were asking about.
That seems like a good thing to me.
-- Grant. . . . unix || die
![](https://secure.gravatar.com/avatar/56f108518d7ee2544412cc80978e3182.jpg?s=120&d=mm&r=g)
On 10/17/22 16:25, Mark Dale via Mailman-Users wrote:
Are you saying that each list member receives 2 copies of an original post addressed only to the list?
All the subscribers are have "nodupes" switched on, and the list is set to replies to go to "This list".
That wouldn't be relevant for an original post addressed only to the list, nor would it be relevant for any user not directly addressed in To: or Cc: of the post.
Ensure you don't have multiple runners processing the same slice of their queues. See https://wiki.list.org/x/4030715 for the procedure to stop ALL Mailman processes and then start it only once.
Examine the Received: headers of both copies to determine the paths that the message takes from poster to recipient.
-- Mark Sapiro <mark@msapiro.net> The highway is for gamblers, San Francisco Bay Area, California better use your sense - B. Dylan
![](https://secure.gravatar.com/avatar/6b50c17f55d7174b281928faf6e87a4d.jpg?s=120&d=mm&r=g)
The problem: subscribers are all receiving duplicate copies of the original post and any replies.
Are you saying that each list member receives 2 copies of an original post addressed only to the list?
Each and every list member receives 2 copies of the post. It is addressed to the list AND CCed to the poster's own email address.
EG. FROM: Me via listname@listdomain.com TO: listname@listdomain.com CC: me@mydomain.com
Ensure you don't have multiple runners processing the same slice of their queues. See https://wiki.list.org/x/4030715 for the procedure to stop ALL Mailman processes and then start it only once.
I stepped through this (results below). After a reboot, there is only one runner.
/var/lib/mailman/bin/qrunner --runner=OutgoingRunner:0:1 -s
Examine the Received: headers of both copies to determine the paths that the message takes from poster to recipient.
I "diffed" the headers of both emails to check, and the message paths are the same.
After the reboot, I posted a test to the list(just the list address, no CC) and now just the one copy of the message is delivered (although it wrote my address into the CC field).
FROM: Me via listname@listdomain.com
TO: listname@listdomain.com
CC: me@mydomain.com
So far so good. I'll keep an eye on the qrunner over the next few days. It came good last time I restarted the qrunner, then went bad. But as you say, there may well have been more than one runner doing their bit.
Here are the steps and results I went through.
# service mailman stop
# ps -fAww |grep python root 432 1 0 Oct01 ? 00:48:57 /usr/bin/python3 /usr/bin/fail2ban-server -xf start nobody 5659 5658 0 00:25 ? 00:00:00 /usr/bin/python /usr/local/bin/mpanel-memory-graph root 5687 5642 0 00:26 pts/0 00:00:00 grep python ////// I SHOULD HAVE CHECKED THAT BEFORE STOPPING MAILMAN
# service mailman start /////// FAILED TO START ... Oct 18 00:30:12 syd systemd[1]: Starting Mailman Master Queue Runner... Oct 18 00:30:13 syd mailmanctl[5791]: Starting Mailman's master qrunner. Oct 18 00:30:13 syd systemd[1]: mailman.service: Can't open PID file /run/mailman/mailman.pid (yet?) after start: No such file or directory
/////// oh? MAYBE IT LIVES SOMEWHERE ELSE # find / -type f -iname "mailman.pid" /////// NO RESULT
///////// hmmm, AM I PANICKING YET? #reboot ///////// phew..., MAILMAN RUNNING AFTER REBOOT.
# pstree systemd─┬─agetty ├─cron .. ├─mailmanctl───python ├─master─┬─anvil │ ├─2*[bounce] ...
# ps -fAww |grep python ////////// LOOKS LIKE ONLY 1 RUNNER. So far, so good.
root 432 1 0 00:36 ? 00:00:00 /usr/bin/python3 /usr/bin/fail2ban-server -xf start list 745 1 0 00:38 ? 00:00:00 /usr/bin/python /usr/lib/mailman/bin/mailmanctl -s start list 751 745 2 00:38 ? 00:00:04 /usr/bin/python /var/lib/mailman/bin/qrunner --runner=OutgoingRunner:0:1 -s nobody 913 911 0 00:40 ? 00:00:00 /usr/bin/python /usr/local/bin/mpanel-memory-graph root 921 908 0 00:40 pts/0 00:00:00 grep python
/////// DID THAT PID FILE REAPPEAR? # find / -type f -iname "mailman.pid" /////// NO RESULT. ... shrug ...
All seems well, the list is delivering single copies of the message (for now).
Thank you Mark for that advice. Very much appreciated.
![](https://secure.gravatar.com/avatar/56f108518d7ee2544412cc80978e3182.jpg?s=120&d=mm&r=g)
On 10/17/22 18:43, Mark Dale via Mailman-Users wrote:
This is expected. See the comment in the code beginning at https://bazaar.launchpad.net/~mailman-coders/mailman/2.1/view/head:/Mailman/... for why we do this.
This is not unusual. It's not a concern.
There should be more. Where are ArchRunner, BounceRunner, CommandRunner, IncomingRunner, NewsRunner, VirginRunner and RetryRunner? Did you edit them out?
What does ps -fwwu list
show?
I suspect an issue with the Debian/Ubuntu package. What is the content of /etc/systemd/system/mailman.service?
All seems well, the list is delivering single copies of the message (for now).
Good.
-- Mark Sapiro <mark@msapiro.net> The highway is for gamblers, San Francisco Bay Area, California better use your sense - B. Dylan
![](https://secure.gravatar.com/avatar/6b50c17f55d7174b281928faf6e87a4d.jpg?s=120&d=mm&r=g)
On 2022-10-18 14:29, Mark Sapiro wrote:
Got it. Thank you.
I hadn't edited then out, but when I ran "ps -fAww |grep python" again just now, they're all present now. Good to know that all those are supposed to be there (in case there's a "next time"). And "ps -fwwu list" shows the same.
# ps -fAww |grep python root 432 1 0 00:36 ? 00:00:20 /usr/bin/python3 /usr/bin/fail2ban-server -xf start nobody 5348 5343 0 03:45 ? 00:00:00 /usr/bin/python /usr/local/bin/mpanel-memory-graph list 5407 1 0 03:47 ? 00:00:00 /usr/bin/python /usr/lib/mailman/bin/mailmanctl -s start list 5408 5407 0 03:47 ? 00:00:00 /usr/bin/python /var/lib/mailman/bin/qrunner --runner=ArchRunner:0:1 -s list 5409 5407 0 03:47 ? 00:00:00 /usr/bin/python /var/lib/mailman/bin/qrunner --runner=BounceRunner:0:1 -s list 5410 5407 0 03:47 ? 00:00:00 /usr/bin/python /var/lib/mailman/bin/qrunner --runner=CommandRunner:0:1 -s list 5411 5407 0 03:47 ? 00:00:00 /usr/bin/python /var/lib/mailman/bin/qrunner --runner=IncomingRunner:0:1 -s list 5412 5407 0 03:47 ? 00:00:00 /usr/bin/python /var/lib/mailman/bin/qrunner --runner=NewsRunner:0:1 -s list 5413 5407 0 03:47 ? 00:00:00 /usr/bin/python /var/lib/mailman/bin/qrunner --runner=OutgoingRunner:0:1 -s list 5414 5407 0 03:47 ? 00:00:00 /usr/bin/python /var/lib/mailman/bin/qrunner --runner=VirginRunner:0:1 -s list 5415 5407 1 03:47 ? 00:00:00 /usr/bin/python /var/lib/mailman/bin/qrunner --runner=RetryRunner:0:1 -s root 5422 5416 0 03:47 pts/0 00:00:00 grep python
# cd /etc/systemd/system/ # ls -la ... mailman-qrunner.service -> /lib/systemd/system/mailman.service
# cat /lib/systemd/system/mailman.service [Unit] Description=Mailman Master Queue Runner After=network.target
[Service] Type=forking PIDFile=/var/run/mailman/mailman.pid ExecStart=/usr/lib/mailman/bin/mailmanctl -s start ExecStop=/usr/lib/mailman/bin/mailmanctl stop ExecReload=/usr/lib/mailman/bin/mailmanctl restart Restart=always RestartSec=3s RestartPreventExitStatus=1
[Install] WantedBy=multi-user.target Alias=mailman-qrunner.service
It seems that it was looking for the PID file in "/run/mailman/mailman.pid" (below) and the above says it lives at "/var/run/mailman/mailman.pid"
Oct 18 00:30:13 syd systemd[1]: mailman.service: Can't open PID file /run/mailman/mailman.pid (yet?) after start: No such file or directory
![](https://secure.gravatar.com/avatar/56f108518d7ee2544412cc80978e3182.jpg?s=120&d=mm&r=g)
On 10/17/22 21:02, Mark Dale via Mailman-Users wrote:
Try changing that to
PIDFile=/var/lib/mailman/data/master-qrunner.pid
I'm only guessing where that is in the Debian package, but
locate master-qrunner.pid
should find it.
/var/run is typically a symlink to /run, but
https://mail.python.org/archives/list/mailman-users@python.org/message/OOVT7...
says you couldn't find a mailman.pid
anywhere.
Oct 18 00:30:13 syd systemd[1]: mailman.service: Can't open PID file /run/mailman/mailman.pid (yet?) after start: No such file or directory
-- Mark Sapiro <mark@msapiro.net> The highway is for gamblers, San Francisco Bay Area, California better use your sense - B. Dylan
![](https://secure.gravatar.com/avatar/6b50c17f55d7174b281928faf6e87a4d.jpg?s=120&d=mm&r=g)
On 2022-10-18 15:37, Mark Sapiro wrote:
Super! That did the job.
#PIDFile=/var/run/mailman/mailman.pid PIDFile=/var/lib/mailman/data/master-qrunner.pid ...
# service mailman stop Warning: The unit file, source configuration file or drop-ins of mailman.service changed on disk. Run 'systemctl daemon-reload' to reload units.
# systemctl daemon-reload # service mailman stop # service mailman start
# pstree ///////// MAILMAN RUNNING # ps -fwwu list ///////// ALL RUNNERS RUNNING
/var/run is typically a symlink to /run, but https://mail.python.org/archives/list/mailman-users@python.org/message/OOVT7... says you couldn't find a
mailman.pid
anywhere.
Yes. For "mailman.pid" nothing is found with either "find" or "locate".
For "master-qrunner.pid" -- no problem ...
# locate master-qrunner.pid /var/lib/mailman/data/master-qrunner.pid
# find / -type f -iname "master-qrunner.pid" /var/lib/mailman/data/master-qrunner.pid
![](https://secure.gravatar.com/avatar/baa72321ff7f0e9dd8a7ce2673cf7de6.jpg?s=120&d=mm&r=g)
On 10/17/22 5:25 PM, Mark Dale via Mailman-Users wrote:
Does anyone have any tips or pointers?
I've seen this type of duplication when there were communications problems that were causing your outbound MTA to send messages multiple times. This usually happens when there are communications problems and your sending MTA doesn't receive the confirmation from receiving MTAs that they have accepted the message. This might be a result of a timeout setting being too low on your sending MTA.
Given that your message to the mailman-users mailing list came to the list twice, which didn't involve your instance of Mailman, I sort of suspect you have lower level / SMTP problems.
I think that your MTA's logs will be a very good place to start looking. At least to see if there is evidence of problems or not.
-- Grant. . . . unix || die
![](https://secure.gravatar.com/avatar/6b50c17f55d7174b281928faf6e87a4d.jpg?s=120&d=mm&r=g)
On 2022-10-18 12:41, Grant Taylor via Mailman-Users wrote:
I've seen this type of duplication when there were communications problems that were causing your outbound MTA to send messages multiple times. This usually happens when there are communications problems and your sending MTA doesn't receive the confirmation from receiving MTAs that they have accepted the message. This might be a result of a timeout setting being too low on your sending MTA.
Thanks for that pointer.
At the moment the Postfix smtpd_timeout = 60s. I think the original default is 300s.
The restart (as per Mark S.'s advice) has got the mail back to one copy. If it goes off the rails again I'll experiment with that timeout.
Given that your message to the mailman-users mailing list came to the list twice, which didn't involve your instance of Mailman, I sort of suspect you have lower level / SMTP problems
That was my bad. I had a cert error and thinking the message hadn't been sent, I resent it. *</:-( (that's my dunce hat)
I think that your MTA's logs will be a very good place to start looking. At least to see if there is evidence of problems or not.
There is one timeout error (unrelated I think) that gets repeated every hour approx. for just one recipient.
Oct 17 18:31:47 syd postfix/smtpd[30094]: timeout after END-OF-MESSAGE from mpv-out-cfd-1.REDACTED-DOMAIN.COM[REDACTED-IP4-ADDRESS]
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On 10/17/22 9:20 PM, Mark Dale via Mailman-Users wrote:
Thanks for that pointer.
You're welcome.
At the moment the Postfix smtpd_timeout = 60s. I think the original default is 300s.
I don't see any problem with having the higher value. Most connections will complete well within that amount of time. 20% of that time in fact. The few that don't will not adversely effect your server.
The restart (as per Mark S.'s advice) has got the mail back to one copy. If it goes off the rails again I'll experiment with that timeout.
ACK
Things happen.
There is one timeout error (unrelated I think) that gets repeated every hour approx. for just one recipient.
So you know what the error would look like and you have the absence of it as the source of the problem you were asking about.
That seems like a good thing to me.
-- Grant. . . . unix || die
participants (3)
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Grant Taylor
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Mark Dale
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Mark Sapiro