[Mailman-Users] Query about low-level SMTP errors

Mark Sapiro msapiro at value.net
Fri Sep 28 17:47:54 CEST 2007

Steve Burling wrote:
>Our mail server is getting the snot beat out of it by spambots, and even 
>though I've turned on pretty aggressive connection rate control and 
>limiting of the number of concurrent connections from any particular bot, 
>we still occasionally hit sendmail's (configured) limit of 70 child 
>processes, at which point we start refusing connections for awhile.  During 
>those times, mailman is also refused connections, resulting in errors like 
>this from smtp-failure:
>Log file: smtp-failure
>     23 delivery failed with code -1: (111, 'Connection refused')
>      1 Low level smtp error: (111, 'Connection refused'), msgid: 
><mailman.9.1190894402.11108.some-list at icpsr.umich.edu>
>      1 Low level smtp error: (111, 'Connection refused'), msgid: 
><mailman.8.1190894402.11108.some-other-list at icpsr.umich.edu>
>Am I correct that Mailman doesn't consider these permanent errors, and will 
>re-try these attempts later?

Yes. This error should result in the message being placed in the retry
queue and being retried every 15 minutes until it is delivered or
DELIVERY_RETRY_PERIOD (default 5 days) expires.

Mark Sapiro <msapiro at value.net>       The highway is for gamblers,
San Francisco Bay Area, California    better use your sense - B. Dylan

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