Thanks for your reply, Eugene. The full message returned by Exim is : 503 Command refused, required Proxy negotiation failed As specified in : /usr/share/doc/exim-4.84/doc/experimental-spec.txt
It is mainly due to non-respect of the 3 seconds timeout, because of high traffic, for instance. Exim is waiting 3s max, that haproxy sends to it the PROXY instruction. I understand that the real problem to solve is the high traffic, but replying by a 503, which will generate to the end user a mail with "503 - REJECT - FORGET ME", is quite hard to explain to the users. So, it is why I thought about a 4xx error. Sylvain Le 21/07/2015 11:46, « Evgeniy Berdnikov » <[email protected]> a écrit : >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 > >-- >## List details at https://lists.exim.org/mailman/listinfo/exim-users >## Exim details at http://www.exim.org/ >## Please use the Wiki with this list - http://wiki.exim.org/ -- ## List details at https://lists.exim.org/mailman/listinfo/exim-users ## Exim details at http://www.exim.org/ ## Please use the Wiki with this list - http://wiki.exim.org/
