Check e-mailaddress

[Yammaski]

I made an "unsubscribe" page where customers can fill in their e-mail.
On submit (unsubscribe button) they 'll be directed to the "thanks" page.
How can I check if the e-mail really exist in my database ?
(Those customers are not logged in, they have to hit the link in the newsletter)
When the e-mail doesn't exists, a message should appear.

[yamaharuss]

where emailaddress = '"& request.form("emailaddress") &"'

of course you need to clean for injection but that's the basic query.

[alexsts]

assuming that link unsubscribe in your email is asp page and look like : www.domainname.com/unsub.asp?id=myemail@isp.com

On your asp page run database verification for this particular email and if it exist display thank you message, if not say sorry email does not exist.