On Wed, 14 May 1997, Greg A. Woods wrote:
> The basic conclusion of my discussions on this issue to date have been
> that I'm not prepared to add a config item for such a list of "valid"
> MXs to smail. The risk of abuse is extremely low, and the affect of
> such abuse is usually trivial, as there must always be a more specific
> MX if the foreign zone wants to eventually receive their email.
Exim does not have such a list. However, it has unwanted relaying
prevention options, which can achieve some of the same effect. If you
were to point one of your MXs at one of our systems, it would reject
mail from the world in general addressed to you, though it would allow
through mail from local systems that are permitted to use this host as a
relay.
The risk of relay abuse (independent of MX pointing) is unfortunately
not extremely low, as several incidents have shown.
--
Philip Hazel University Computing Service,
ph10@??? New Museums Site, Cambridge CB2 3QG,
P.Hazel@??? England. Phone: +44 1223 334714
