On Mon, 23 Feb 2004, David Woodhouse wrote:
> For sender verification callouts you are 100% correct.
>
> For _recipient_ verification callouts I think Exim's current behaviour
> is suboptimal.
I have to confess to brain fade. I thought Exim already used the
message's actual sender when doing recipient callouts. However, when I
look at the code, I see that it does not. I have been under this
delusion for quite some time...
There is nothing in the ChangeLog that suggests this has ever been
changed since recipient callouts were invented at the start of Exim 4.
Now that I think about it some more, however, I suspect that "<>" was
used so as to prevent the next server from doing yet another callout. If
the current MTA has already called out to verify the sender address, it
is wasteful - and discourteous - to callout-verify it again.
--
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