How to verify email at Mail Server?

[adambradley]

Hi everyone,

I know that there are countless examples of how to check the validity of a well-formed email address but I want to go one step further......

I want to check that the email address entered actually exists on the mail server - somehow doing a DNS lookup on the MX record perhaps?

Can anyone show me how to do this please?

[arnihr]

Yeah, take a look at this Clever Email Validation Function 🙂

http://www.zend.com/codex.php?id=449&single=1

I haven't tried it, but hey, if it doesn't work, try fixing it 🙂

Hope it helps, Arni

[adambradley]

Yes, that looks like it works fine - although it does need slight modification due to the author being Korean.

I think that with the first check (for a well-formed email address), that this would need to be modified because it always reports that the email form is not right even when it is.

.....but the actual mail address being verified at the mail server seems to work perfectly.

Thanks for pointing me in the right direction.

Adam

[Anon]

Just read your messages about verifying emails at a server, but cannot locate the code. Are you able to share it with me?

Thanks

[Anon]

This code proves whether an address is well-formed, whether the domain exists, whether a mail server is specified in the DNS for this domain, and whether or not the mail server can successfully be connected to.

However, despite good intentions, it doesn't prove whether the email address in fact exists on the mail server.

If you connect to a mail server for domainx.com (just an example) -- (you can do this manually via "telnet mail-server-for-domainx.com smtp" from a command prompt), and ask it to send or receive mail for:

[e-mail]

It will still respond with something like:

250 OK - Recipient <[e-mail]>

Even if the mailbox does not exist on the server.

On some mail servers, you can use the VRFY command to check the validity of an email address -- however the vast majority of servers have disabled this command for security reasons -- so you will either receive an error, or receive an "OK" response no matter what you type in.

In sum, it is ususally not possible to check the validity of an email address, except by attempting to send mail to the address.

S.