Re: [exim] Sender verify at extreme

On Thu, 2007-07-05 at 22:52 +0100, Phil (Medway Hosting) wrote:
> You don't need callouts full-stop. They are abusive behaviour and should not
> be used.

That's not *quite* true, Phil. Some people regard them as abusive if
they are done without any limitations whatsoever.

However, they can be extremely useful in cases such as hosting farms,
dedicated server providers and colos where all the mail goes out through
a smarthost - calling back to *your own network* to check whether or not
a sender is valid is very useful indeed.

Graeme