Re: [Exim] Opinions sought: hosts_max_try

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Author: Philip Hazel
Date:  
To: Tabor J. Wells
CC: exim-users
Subject: Re: [Exim] Opinions sought: hosts_max_try
On Fri, 30 Aug 2002, Tabor J. Wells wrote:

> Where them = the less preferable MX values? Why then only try one?


Because Exim has already exceeded the hosts_max_try setting.

> To me the goal of my mail servers is to get mail off of my queue and
> onto a MX for that domain as quickly as possible. To me that means
> trying as many MX hosts as possible.


In that case, set hosts_max_try=1000. Remember that each try might
involve a timeout of 5 minutes.

> So if example.com has 10 unique IPs at MX 1, 10 at MX 2, and 10 at MX 3 and
> my hosts_max_try is set to, say, 5 then I'd expect it to try 5 hosts at MX1,
> if all fail then try 5 at MX2, if all of those fail then try 5 at MX3.
> Not 5, 1, and 1. Or perhaps there needs to be another option
> hosts_max_try_per_mx? :)


Well, I did consider making hosts_max_try operate per MX value, as you
suggest. But given that it's already failed on a fair number (I don't
expect people to set hosts_max_try less than 5), I compromised by going
for 1. That could be made 2 or more, but I don't think it really
matters much in practice.

Remember that at some subsequent queue run, the hosts you tried last
time might not have reached their retry times yet, so that time it will
try some other hosts.


--
Philip Hazel            University of Cambridge Computing Service,
ph10@???      Cambridge, England. Phone: +44 1223 334714.