> It's not a restriction; it's just basic system administration
> practice.  If a host has any possibility of emitting E-mail with its
> domain name in the return address, then there must be an A or MX
> record in the DNS, pointing to an SMTP server, so that replies can
> come back.

Agreed.  I guess I misread "at least an MX record" as meaning "at least
an MX record" (ie, "an MX record and possibly other stuff") rather than
"an MX or A record". :-)  (Actually, I don't quite agree, but the
differences are quibbles: I'd say that it needs an MX or A or AAAA (or
A6, if that ever coems back), where A/AAAA are selected between based
on the address family over which the mail was sent, and if there is an
MX then at least one MX must have an address in the address family over
which the mail was sent.)

					der Mouse