On Wed, 8 Apr 1998, Adrian J Bool wrote:
> We are playing with exim with,
>
> remotemail:
> driver = domainlist
> transport = remote_smtp
> route_list = "* $domain bydns"
> host_find_failed = fail_hard
>
> in place of the more usual,
>
> lookuphost:
> driver = lookuphost
> transport = remote_smtp
>
> To have the same effect as lookuphost, but bouncing mail if the destination
> domain does not exist.
I've missed something. If lookuphost gets a non-existent domain, it
bounces mail. So what is different about your world?
> However, if a mail enters our server with both a non-existent recipient and
> sender, exim freezes the returned error message. Why? One would think the
> same process would be applied to the error message - when exim discovers that
> the new message has a non-existent domain for the new recipient it would
> return the message to the sender - in this case postmaster.
The envelope sender of Exim's error messages is not postmaster, it is
the empty sender, as required by RFC 821. Thus it can never generate an
error message to the sender of an error message. This is a protection
against cascades.
--
Philip Hazel University Computing Service,
ph10@??? New Museums Site, Cambridge CB2 3QG,
P.Hazel@??? England. Phone: +44 1223 334714
--
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