On Tue, 7 Nov 2000, Bruno Vuillemin wrote:
> When performing a "sender_verify" action on incoming mail, it seems that
> the various lookuphost routers are tested.
Indeed. Think about it. What does "verify" mean? To Exim, "verify an
address" means "see if you could send a message to the address". How can
it do this? Answer: run the address through the directors and/or
routers, because that's what it would do if it had to send a message to
that address.
You *can*, however, if you want to, make this different to the case when
really sending a message. Check out the verify_only, no_verify, and
several other related options. It is possible to arrange to use an
entirely different set of routers/directors for verification, if you
really want to. However, in this case, that isn't really the problem at
all.
> Last remark : web.directnic.com doesn't have any MX (at the time of writing)
> but does have an A record.
... so the lookuphost driver should manage to verify it.
BUT:
It appears that the DNS for web.directnic.com is broken. Exim will
attempt to look up an MX record before looking for an A record, as it is
supposed to do. My test script for this gives the following:
$ mdig web.directnic.com
MX lookup yielded SERVFAIL
web.directnic.com. A 206.19.41.124
When Exim gets SERVFAIL (name server failure), it cannot proceed. It
does not know if there is an MX record or not. It is not allowed to look
for an A record unless it knows there is no MX record. That is why it
gives a temporary verification error (4xx).
--
Philip Hazel University of Cambridge Computing Service,
ph10@??? Cambridge, England. Phone: +44 1223 334714.
