> -----Original Message-----
> From: Philip Hazel [mailto:ph10@cus.cam.ac.uk]
> People gave up on VRFY a long time ago. Possibly because its use was
> mis-understood. Some MTAs always give a positive response;
> some always give a negative response. The net result is that VRFY can't
> be usefully used for anything.
Some MTAs will always give a positive response to callout verification, too,
because they accept everything and then bounce what they can't deliver. I
believe this is true, for example, of any host that's running Exchange 5.5.
It's also true of backup MX's at a lot of sites.