Re: [exim] Proxy Error 503. Can change that ?

On Tue, Jul 21, 2015 at 10:53:36AM +0200, Sylvain Donnet wrote:
>
> I have two servers, one with Haproxy and its send-proxy experimental
> feature, and a Baruwa server, with exim installed on it. Sometimes,
> I got bunches of proxy 503 errors, due probably to overloads in
> traffic. They are very annoying for my customers.

Does Haproxy replies with SMTP status code 503 on overload?
If so, this proxy should be fixed, not Exim.

First, code 503 have meaming "Service unavailable" for HTTP,
but for SMTP code 503 is "Bad sequence of commands" and this
is completely unrelated with proxy overloads.

I think that correct behaviour of proxy in case of overload is simply
do not accept() new connections, then Exim as client could get timeout
on connect() and keep mail in queue, retrying later.

> Is it possible to change the 503 into a 45x error, just to tell to
> the others SMTP MTAs to retry later (I cannot compile/recompile
> exim, it is distributed by Baruwa) ? Or any other solutions to avoid
> a returning mail to senders ?

Wrong approach, IMHO.
--
Eugene Berdnikov