Quoting Wayne Pascoe:
>> (http://www.exim.org/eximwiki/FAQ/Policy_controls/Q0730).
> I think I'm being thick, but I can't really see the major difference
> between what is in the Wiki and what Juha posted. Could someone please
> enlighten me?
Actually, Juha's version is also in the Wiki
(
http://www.exim.org/eximwiki/AuthenticatedSmtpUsingCourier).
The difference is: The simple version (without ${extract...}) relies on
authdaemon returning FAIL to _deny_ access, while the other one expects
"address=something" to _allow_ access, which is the better approach from
security point of view, I'd say. This might be nitpicking, but better
safe than sorry.