Re: [Exim] Invalid Sender: headers

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Author: Philip Hazel
Date:  
To: William Thompson
CC: Phil Chambers, exim-users
Subject: Re: [Exim] Invalid Sender: headers
On Tue, 6 May 2003, William Thompson wrote:

>    deny    !hosts = +local_net : +secondary_mx
>        !verify = sender/callout=30s

>
> How would you write that as a require


I think the answer was already given. But it may be useful to point out
that inserting the relevant AND and OR connectors may help in
understanding how everything fits together. Between the conditions of an
individual ACL statement, you must insert AND. So you can read the above
as

"deny if hosts are not (in local_net or secondary mx) AND verify sender
fails"

For a "require" you need the opposite condition to a deny. Negating
the conditions you get

"require hosts to be in (local_net or secondary_mx) OR verify sender
succeeds"

You can't write that as a "require" statement, because there is no way
of having multiple conditions connected by OR.

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