Ultrix 4.0 sendmail MX handling

[John Haxby]

In article <412 at vtserf.cc.vt.edu>, marchany at vtserf.cc.vt.edu (Randy Marchany) writes:
|> In article <1990Sep5.134625.16191 at ni.umd.edu> louie at sayshell.umd.edu (Louis A. Mamakos) writes:
|> >Has anyone else noticed problems with MX forwarding in sendmail?  Here's
|> >the problem that I've had:
|> >
|> >In the DNS, there are some MX records for TRANTOR.UMD.EDU:
|> >
|> >TRANTOR.UMD.EDU	IN	MX	10 TRANTOR.UMD.EDU.
|> >		IN	MX	20 CAMELOT.UMD.EDU.
|> >
|> >louie
|> 
|> He goes on to state that whenever TRANTOR goes down, CAMELOT tries to
|> deliver to  TRANTOR and on failure, opens a 'connected to itself' which is
|> the problem. Apparently, the list of MX forwarders is not trimmed to
|> those with lower preferences than itself. This used to work on Ultrix
|> 3.1. 
|> 
|> We've run into the same problem here at our site

MX records work without any problems in V4, provided that you don't that an
MX record for a host doesn't include itself :-(

However, the good news is that the reason for this is that the $w macro is
defined to be the unqualified name of the host (eg TRANTOR) instead of the
FQDN (eg TRANTOR.UMD.EDU) -- the solution is to define $w to be the FQDN
explicitly in the sendmail config file; this, of course, may throw up
problems in the config file because it assumes that $w is unqualified.
-- 
--
John Haxby
Digital				<jch at wessex.rdg.dec.com>
Reading, England		<...!ukc!wessex!jch>