Verify an Email Address
Sometimes it is nice to verify whether an email address actually exists:
telnet mx1.example.dk 25
Trying 1.2.3.4...
Connected to mx1.example.dk
Escape character is '^]'.
220 mail2.nbi.dk ESMTP Postfix
helo me.svalgaard.net
250 mail2.nbi.dk
mail from: [email protected]
250 2.1.0 Ok
rcpt to: [email protected]
250 2.1.5 Ok
quit
221 2.0.0 Bye
Connection closed by foreign host.
If it doesn’t say250 2.1.5 Ok after the rcpt to, the address doesn’t exist.