>True. But it sounds like he wants to verify a voluntarily entered email address for a list, and verifying the user and server is about as far as you can go.

And I've seen some bots filling such forms and with regular email addresses in the appropriate fields. I guess only a human eye can evaluate it in a sufficiently reasonable manner.

>>>You are verifying that the user at that server exists.
>>
>>And if it does, still means nothing. It could be one of the places used by spammers where they generate thousands of addresses daily (am: on a daily basis), and they use them perhaps for just a few days, to fool the by-address filters. So these addresses exist, in the sense that some real emails were sent from them. Doesn't imply that there ever was anyone manning that station.