Re: [Exim] sender_verify, lookuphost MX and A records

> However there are definitely people who flat-out refuse to add even a
> few sensible MX records to their DNS, including at least one reasonably
> large .EDU site in the States, if they see that things will continue to
> work (from their point of view) without them.

Then it is time to add something to that point of view. How about:

X-RFC-Warning: dom.ain has no MX record

I love Exim for its X-RBL-Warning, because it tags mails as originating
from poorly administered sites. I see no reason not to extend this to
other problem areas.

Michael