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From: gmp@rayssd.ssd.ray.com (Gregory M. Paris)
Newsgroups: comp.mail.sendmail
Subject: Re: resolv options when rewriting sender (inconsistencies).
Summary: A way around turning off RES_DEFNAMES and RES_DNSRCH.
Keywords: dot, period
Message-ID: <8144@rayssd.ssd.ray.com>
Date: 13 Jul 90 11:57:25 GMT
References: <1990Jul3.020637.28385@ulrik.uio.no> <5764@jhunix.HCF.JHU.EDU> <1990Jul10.151028.20873@ulrik.uio.no>
Reply-To: gmp@quahog.ssd.ray.com (Greg Paris)
Organization: Raytheon Submarine Signal Division
Lines: 28

Please note the quoted text below in reference to the following line
from sendmail's deliver.c.
/* 	_res.options |= RES_DEFNAMES | RES_DNSRCH;	/* XXX */

In article <1990Jul10.151028.20873@ulrik.uio.no> obh@ulrik.uio.no (Ole Bj|rn Hessen) writes:
> _res.option is a global variable and thereby affects the expansion of the
> $[ $] macro. The header is expanded in the smtpdata routine while this option
...
> >somewhere in your sendmail.cf.  If that's true, then there's no need to go
> >tacking on additional domain names when trying to get MX's and their
> >addresses.  
...
> Right, this option should not be set when sendmail looks up MX records.
> Neither when sendmail tries to open connections to recipient host.

I think it's overkill to turn of RES_DEFNAMES and RES_DNSRCH to avoid
silly MX lookups.  I commented out the above code and instead added
a single line change to getmxrr which tacks a dot onto each MX hostname.
This solution avoids affecting $[$] by turning off two _res.options
and also keeps the resolver from tacking stuff onto the end of MX
host names.  I've been using this change for a couple months now and
it works just fine.


-- 
Greg Paris <gmp@quahog.ssd.ray.com>
{uiucdcs,uunet}!rayssd!gmp
Princess Di is wearing a new dress.