Greg Woods writes:
> After all, if you really want to handle e-mail for someone it should be
> trivial for them to add an MX pointing at you. It is irrelevant how you
> eventually deliver the mail if indeed you're the primary MX.
Philip Hazel responds:
> Anybody can add an MX pointing at you. Have I misunderstood you, or does
> that give them the power to force you to relay to them? Surely I've got
> this wrong...
This was my initial reaction too, but there are different reasons sites
want to control relaying. Greg's mechanism is perfectly adequate for
preventing spammers using you as a relay site to bombard the whole world
from (with the result that you get put on everyone's hate list as well).
If a recipient domain surreptitiously creates an MX record pointing to
you, they certainly can't complain about you relaying mail to them!
Chris Thompson Cambridge University Computing Service,
Email: cet1@??? New Museums Site, Cambridge CB2 3QG,
Phone: +44 1223 334715 United Kingdom.
