[thelist] Checking to see that an email account exists

Simon Willison simon at incutio.com
Wed Jul 17 09:27:01 CDT 2002

At 10:09 17/07/2002 -0400, you wrote:
>Does anybody know the preferred/easiest method for asking a mail server if a
>particular email address is valid?  Is there some sort of anonymous POP3
>command that does it?  any SMTP commands?  Telnet?

It's not really possible. You can open a port to the mail server and ask if
the username exists, but many mail servers are configured to say "yes" to
all requests and handle forwarding mail to non existent accounts later on.

There's a good article on this kind of thing (with respect to PHP but tips
applicable to any language) here:



Simon Willison

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