Dear Postfix Community,
after reading the documentation "Postfix Architecture Overview", I thought that
"qmgr" would handle operations between the different queues correctly and
despite any connection or performance issues.
Our company uses Mailman via Postfix on a regular basis for mailings with up to
50.000 recipients. We did not touch the standard configuration yet, except the
"relayhost" entry.
During our last mailing, an analysis of the log file showed, that the number of
messages sent thru postfix was not about 50.000 as expected, but near the
factor 10 of it. More than a hundred times, the following warnings appeared in
the log:
________________________________
Jun 5 15:08:11 172 postfix/qmgr[31501]: warning: mail for 172.29.101.13 is
using up 20000 of 20000 active queue entries
Jun 5 15:08:11 172 postfix/qmgr[31501]: warning: you may need to increase the
main.cf smtp_destination_concurrency_limit from 20
Jun 5 15:08:11 172 postfix/qmgr[31501]: warning: please avoid flushing the
whole queue when you have
Jun 5 15:08:11 172 postfix/qmgr[31501]: warning: lots of deferred mail, that
is bad for performance
Jun 5 15:08:11 172 postfix/qmgr[31501]: warning: to turn off these warnings
specify: qmgr_clog_warn_time = 0
________________________________
I guess that the relay host accepted the messages only with huge delays, so the
active queue filled up quickly. There were no log entries concerning the
deferred queue. In the log file (> 300 MiB), the delay values are increasing
during the mailing. It seems that the relay host was either overloaded or
misconfigured. Nevertheless, it was the first occurrence of any postfix problem
during our mailings and I still have no explanation, why a great number of
recipients got the same message multiple times.
Do you know about any behavior of the qmgr, that could explain the duplicate
transmission of messages?
main.cf:
________________________________
smtpd_banner = $myhostname ESMTP $mail_name (Debian/GNU)
biff = no
append_dot_mydomain = no
readme_directory = no
smtpd_tls_cert_file=/etc/ssl/certs/ssl-cert-snakeoil.pem
smtpd_tls_key_file=/etc/ssl/private/ssl-cert-snakeoil.key
smtpd_use_tls=yes
smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache
smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache
myhostname = xxx
smtpd_banner = $myhostname ESMTP
alias_maps= hash:/var/lib/mailman/data/aliases
alias_database = $alias_maps
mydomain = xxx
myorigin = /etc/mailname
mydestination = xxx
relayhost = xxx
mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128 xxx
mailbox_command =
mailbox_size_limit = 0
recipient_delimiter = +
inet_interfaces = all
inet_protocols = all
message_size_limit = 104857600
________________________________
Kindest regards,
Tobias Schwartz
German Bar Association
IT Department
--
Deutscher Anwaltverein (DAV) e. V.
Littenstraße 11, 10179 Berlin
Phone +49 30 726152-160, Fax -194
schwa...@anwaltverein.de<mailto:schwa...@anwaltverein.de>,
www.anwaltverein.de<http://www.anwaltverein.de/>
