email validation

[omoutop]

Hello all.
My current problem is a way to determine if an email address actual exists.
I can validate its syntax (with regular expressions)
I can validate if the domain exist (with checkdnsrr)

And i seek a way to determine if the email actually exists.
I need to check an email list, and clean it of invalid emails). The list has around 3k emails.

Can this be done with php? Ad if yes, how? Where do i begin and how?

[Anyango]

I don't think it is possible, or maybe you can write some scripts to talk to mail server for those domains and ask if that email exists but i ve never seen it somewhere. Good question though and would be cool if someone has a solution

[wheel]

3000 emails? Assuming they're yours, and they're opt in, then I wouldn't do this through a program. Just send an email asking them to opt in again. Those that optin were valid, those that don't, are either not interested or invalid.

I get these kinds of emails from forums sporadically.

[omoutop]

you know of any such programm? I prefer a free one, but i can pay or one also (providing it can accomplish my needs)

And yes, all the emails are legit registered emails to various services in our sites (we assume around 80-85% of them to be valid, but just in case, we would like to clean out lists)

[willybfriendly]

You can use sockets (fsockupen() to do na SMTP probe of the email address.

This is not foolproof since servers are configured differently. For instance, if the server is using an alternate port for email (i.e. $email_port != 25), catch all addresses, etc. might effect the results.

You can find examples of scripts with a search.