On Thu, 21 Jun 2007, Graeme Fowler wrote:
> I agree with Philip. There are several sections of the Exim config which
> it is possible to remove and still have a fully functioning system.
Indeed. There are also many ways in which you can configure Exim to
shoot yourself in both feet. The default configuration is "safe". If you
change it, you need to know what you are doing - that's my "hard-line"
attitude, I think.
> only has three lines (see Ch.40). It is possible to remove all the
> defaults and replace them with:
>
> acl_smtp_rcpt = do_not_use_this_acl
Or even
acl_smtp_rcpt = accept
> I can think of a number of situations where it's quite possible no
> retries at all would want to be done - think time-critical delivery such
> as for alarm systems (although using SMTP for alarm propagation is a bad
> idea, I know of several fire alarm systems that use it!).
Actually, Exim being the flexible thing that it is, one can configure
that explicitly with this retry rule:
* *
That is, for all hosts/addresses, for all errors, give up immediately
(no retry times). But I still don't like the idea of putting a default
into the code.
> Perhaps the docs need to be amended to state categorically that:
>
> Removal (or omission) of the retry section, or inclusion of the section
> with no rules, results in there being no retry attempts on any sort of
> error condition. All errors will, therefore, immediately be treated as
> permanent.
It already says (chapter 32) "If there are no retry rules, temporary
errors are treated as permanent", but I will expand on that, and also
re-iterate it in section 7.5 ("Default retry rule").
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--
Philip Hazel University of Cambridge Computing Service
Get the Exim 4 book: http://www.uit.co.uk/exim-book
