On Wed, 14 Sep 2011 20:45:43 -0000, "Sparks, Michael" said:
> We don't have an A or CNAME for lists.law.lsu.edu because the MX for that
> name points to another box that receives mail for several domains and forwards
> it on to the box running LISTSERV. I've always thought that would cause
> problems to have an A for that name when mail should be delivered elsewhere.
> Maybe that would not be a problem?

If it's a problem, you have *bigger* problems - systems that can't follow the SMTP
spec as it's been since at least RFC974 (Jan 1986).

If there's an MX for an address, that is to be used in preference to an A
record for the same name.  We do it *all* the time for boxes that don't
do their own mail service:

;; ANSWER SECTION:
ginger.cc.vt.edu.       14400   IN      A       198.82.161.240
ginger.cc.vt.edu.       14400   IN      MX      0 mail.vt.edu.

See RFC5321, section 5.1:

   If one or more MX RRs are found for a given name, SMTP systems MUST
   NOT utilize any address RRs associated with that name unless they are
   located using the MX RRs; the "implicit MX" rule above applies only
   if there are no MX records present.  If MX records are present, but
   none of them are usable, this situation MUST be reported as an error.

############################

To unsubscribe from the LSTSRV-L list:
write to: mailto:[log in to unmask]
or click the following link:
http://peach.ease.lsoft.com/scripts/wa.exe?SUBED1=LSTSRV-L&A=1