[Mailman-Users] Soft bounces....

Charles Gregory cgregory at hwcn.org
Fri Apr 3 15:50:19 CEST 2009

On Fri, 3 Apr 2009, Brad Knowles wrote:
>>  Yahoo expects me to respond promptly to 5xx bounces, disabling any
>>  subscriptions, otherwise it starts generating 'greylist' 4xx bounces for
>>  my mail. Unfortunately, if I try to lower the bounce threshold, the
>>  now-daily occurence of 4xx bounces guarantees that all yahoo addresses
>>  will end up disabled. Is there any way, short of fiddling with and
>>  recompiling from source, to separate 'hard' bounce handling from 'soft'
>>  bounce handling, or to change the 'scores' that each accumulates?
> Thing is, Mailman doesn't see the 5xx or 4xx codes directly.  It hands 
> the messages off to your MTA, and your MTA sees those codes.

Good point. Even though I'm seeing 'deferals' in the MTA logs, they 
don't go long enough to generate '4 hour warnings' that mailman 
would have to handle as a 'soft bounce'. Just verified this in the logs
(where I should have looked first! LOL). Excellent! Thanks!

> Since we do not, and we cannot, have direct access to the 5xx versus 4xx 
> response codes from Yahoo!, I don't think it makes a lot of sense to try 
> to modify the code to treat a bounce resulting from a permanent 5xx 
> response code any different from a "delayed message" notice resulting 
> from a temporary 4xx response code.

(nod) No, all I need to do now is lower the threshold so Yahoo won't see 
so many attempts to send mail to 5xx addresses.... Then maybe they'll stop 
doing so many 4xx delays of my mail (not just a mailman problem, 

> Set up your MTA to handle Yahoo! separately from other sites, so that 
> any slow downs there don't slow you down in getting to other domains, 
> and vice-versa.

I use postfix, so the performance of yahoo delivery doesn't really impact 
other mail, other than the impact of the extra load of retries...
Though I find it ironic that Yahoo sends lots of mail to me for unknown 
users.... :)

Thanks again!

- Charles

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