[Mimedefang] Re: On pinheaded ISP's (sort of OT)

[Joseph Brennan]

--On Thursday, February 1, 2007 10:27 -0600 Cam <bcp1 at craqed.com> wrote:

> Tempfailing is also useful for whipping on known spamsites.  I never
> outright blocked them, but would instead consistantly reject 99% of
> messages (all except destined for abuse/root/postmaster/etc at our sites)
> from historically nasty spam hosts with a 471.  that way if it was a legit
> site, they would eventually contact me due to queue size.


If you don't know for certain whether it is legit, DON'T do this.

Sites that allow users to forward will inevitably forward some spam
along with the rest.  I do not get a good feeling when some site
decides to tempfail mail they have no intention of ever accepting,
and our queues rise and service level drops.  Give us a break.  If
you don't want it give us a 550 and be done with it.

I've got special queue runners going to bounce mail earlier for a
few destinations that pull this trick.

Joseph Brennan
Lead Email Systems Engineer
Columbia University Information Technology