smtp vrfy

[Koopmann, Jan-Peter]

> *breaks out the clue stick*
> 
> Callouts are considered abusive by many servers-- you probably want to
> be VERY
> VERY CAREFUL about doing this...  Personally I don't run it at all,
but
> my spam
> setup is such that I don't need to...

Are they talking about sender address verification? The way I read it he
is trying to do the opposite and ask his inbound receiving mailer which
would be a wise thing to do and has nothing to do with callouts. Might
be wrong though... :-)