Re: [EXIM] Reverse lookups on EXIM

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Author: Philip Hazel
Date:  
To: Paul Brown
CC: exim-users
Subject: Re: [EXIM] Reverse lookups on EXIM
On Tue, 14 Apr 1998, Paul Brown wrote:

> the question is essentially.. is a reverse lookup making the connection to
> the mail server take a few seconds, or something else. Also, is there any
> way to speed this up?


If the mail server is configured to do reverse lookups, it will do them.
It does not have to be so configured. Reverse lookups are necessary if
any constraint (e.g. sender_host_reject) contains wild card host names.
If the host names are explicit, the daemon does a single forward lookup
when it starts up.

Likewise, the default configuration is set up to do RFC 1413 ident
callbacks. It seems that too many systems time these out instead of
giving an immediate "connection refused". The timeout was reduced from
60 to 30 seconds in Exim 1.90 because of this.

-- 
Philip Hazel                   University Computing Service,
ph10@???             New Museums Site, Cambridge CB2 3QG,
P.Hazel@???          England.  Phone: +44 1223 334714



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