> -----Original Message-----
> From: Tor Slettnes [mailto:tor@slett.net]
> Finally, maybe as a consequence of the last point, some large
> ISPs such
> as AOL will unconditionally blacklist any sites they find to be
> performing sender callout verifications against their servers.
And some sites accept everything at RCPT time, then reject later, which
defeats the purpose.
Also, some sites will blacklist you if you give them too many bad
recipients. I think Yahoo is one. That means that a spam run from someone
forging yahoo.com addresses can result in you not being able to send mail to
Yahoo, if you're running callback verification.
I used to run it, but decided it wasn't worth the risks.
