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From: urlichs@smurf.ira.uka.de (Matthias Urlichs)
Newsgroups: comp.protocols.appletalk
Subject: Re: MacTCP and MX Domain Name Support
Message-ID: <1261@smurf.ira.uka.de>
Date: 1 Dec 89 16:40:44 GMT
References: <Added.gZR8Bdm00UkT4nmE9i@andrew.cmu.edu>
Reply-To: urlichs@smurf.ira.uka.de (Matthias Urlichs)
Organization: University of Karlsruhe, FRG
Lines: 24

In comp.protocols.appletalk Tom Biddulph <starnine!bid@uunet.UU.NET> writes:
< [...] . We pass the destination "hostname" directly to the MacTCP name
< resolver. If you have the "domain nameserver" option checked, it is passed
< to this system for resolution. I don't think that MacTCP knows anything about
< the difference between asking for
< an "A" address and an "MX" address. It just wants the IP address for the
< specified system.
< 
MacTCP doesn't know anything at all about getting addresses from name servers.
The domain name resolver code is linked to your application (dns.o), and only
understands "A" records. MX-type records should be handled different from
A-records anyway.

<Let me think about things a bit more to see if I can come up with any type of
<work-around. Your suggestions will be welcome, but if the only resolution is in
<changes to "MacTCP", you won't see these for a while since we rely on APPLE for
<this software.
There is no workaround, or rather, getting an A record from the DNS and
sending the mail to your default SMTP host if it fails already _is_ the
workaround.
Putting DNS support into your mailer would be the better solution.
Suggested reading are of course the appropriate RFCs...
-- 
Matthias Urlichs