On Wed, 17 Sep 2003, Walt Reed wrote:
> Many mail servers fall back to the A record when no MX exists.
I have been saying for many years that it was time this old backwards
compability rule, which dates from the introduction of MX records, was
abolished. Certainly since before I started to write Exim, because I
patched an appropriate per-domain option into Smail.
> BTW, anyone have an ACL that rejects mail when the sender envelope
> domain does not have a valid MX record?
You can do this by making use of the mx_domains option on a dnslookup
router that you set up for use when verifying senders (check out the
verify_only and verify_sender options).
--
Philip Hazel University of Cambridge Computing Service,
ph10@??? Cambridge, England. Phone: +44 1223 334714.
Get the Exim 4 book: http://www.uit.co.uk/exim-book