Hi !!
>> None of this is true for callouts. We are forced to expend server
>> resources in handling callouts. Our ability to receive our own
>> email is impaired by other people's use of callout verification.
>> (How well would your mailserver stand up to receiving four orders
>> of magnitude more connections per second than it should?)
>
> Verizon did this to me once. A spammer was forging one of my domainnames
> in a spam run so VZ was issuing 70-100 callouts/second to my server. I
> had no usable mail service for hours, so I blacklisted their callout
> farm. Then they blacklisted me for blacklisting their callouts.
this looks like a faulty implementation, i'm sure that this 70-100
callouts/second to your server where also a problem for Verizon
all of this drives to no place ... wouldn't it be more practical to
recommend good callout practices ? in fact callouts are probably more
expensive at the sending side that at the receiving side so it's good
for both sides to reduce it's use to the minimum. Not doing callouts
for whitelisted senders/hosts, not doing them when spf=pass and doing
them at the last stage, etc ...
as callouts are good to stop spam, to enhace email realibility by
ensuring that no invalid return-path is used (also as part of BATV),
to prevent receiving bounces for invalid users, etc ... people won't
stop using them and blacklisting each other only degrades email more
than just being smart at sending/receiving callouts.
--
Best regards ...
----------------------------------------------------------------
David Saez Padros http://www.ols.es
On-Line Services 2000 S.L. e-mail david@???
Pintor Vayreda 1 telf +34 902 50 29 75
08184 Palau-Solita i Plegamans movil +34 670 35 27 53
----------------------------------------------------------------
