I'm working on a project which requires me to know with extremely high probability the availability of an e-mail account on a mail server (let's use Hotmail in this example.) I know that the VRFY command is often ignored (Hotmail says "I'll take a message" or something of the like when I try it,) so I'd like to know the best way to go about this. I've read that the following should be fairly accurate, but Hotmail gives me a pain about it:
EHLO hotmail.com
MAIL FROM:<[email protected]>
(Hotmail gives me the below error here)
RCPT TO:<[email protected]>
The error Hotmail gives me is:
550 SC-001 Mail rejected by Windows Live Hotmail for policy reasons. Reasons for rejection may be related to content with spam-like characteristics or IP/domain reputation problems. If you are not an email/network admin please contact your E-mail/Internet Service Provider for help. Email/network admins, please visit http://postmaster.live.com for email delivery information and support
Connection closed by foreign host.
[root@iago ~]#
This isn't just a Hotmail problem; similar things have happened when I try it with other e-mail hosts.
On a side note, oh how I wish the finger protocol was still widely used...
You can thank the spammers for the disabled VRFYs. What you could do is to do the mailout and weed out the email addresses for the emails that bounces back.
Edit: You can do the first weed out by buying the service from Verify Email address. I do suggest that you allow for the people to opt-out on future correspondence.