Re: [exim] Sender verification

Matthew Byng-Maddick wrote:
> On Fri, Oct 28, 2005 at 08:48:01AM +0200, Ian FREISLICH wrote:
> [callouts]
> > Ah, you folk in acedemia might not then have encountered the
> > argument from a paying customer "I don't care if the admin of the
> > site hosting my prospective customer is a fool, your decision to not
> > accept their mail on the basis of the failed callout is costing me
> > potential business".
>
> The only correct response to this argument is to give them a full
> unfiltered mail feed, I'm sure they'll ask you to implement whatever
> anti-spam methods seem reasonable soon enough.

I have people that are happy to filter their spam manually so that
they don't miss a business opportunity.

> I know this sounds harsh, but callouts are just one of many methods
> used.

I know that. This doesn't stop the practise from being at best
misguided. When, after a little mental expenditure you examine the
consequences for others you continue to do so you no longer fall
into the misguided category. From my servers you will only know
if the recipient to a callout is valid if you go as far as the DATA
command. Harsh, but that's my protest against this practice.

> I've seen legitimate mails constructed by businesses who don't have
> a clue how to use email be trapped by SA, so obviously SA is costing
> them potential business too. If they want a full unfiltered mail feed,
> I'm sure they can have it...

Yes, and that happens and I do give people unfiltered mail feeds
if that is what they want, but neither my quoted post nor your
response is a valid arument for or against sender callouts.

Ian

--
Ian Freislich