quote:
Error checking is more important than idiot proofing
Always double check email addresses. Always make sure you request them at least twice. Take a contact phone number as well if possible. That way you will never lose contact and you can ask why they have not been online.
The fact is that it's not possible due to the way the emails work. If you could do this all a spammer would need to do is run a list of emails through a program and sell off all the ones that work to other spammers...