getting “530 5.7.0 Must issue a STARTTLS command first.” error when sending mail via netcat

Question

I\'m trying to send an email with netcat, this is what i get:

****-MacBook-Pro:~ ***$ nc smtp.gmail.com 25
220 mx.google.com ESMTP h8sm66301168eew.16 - gsmtp         


        

Answer 1

STARTTLS is an extension to plain text communication protocols, which offers a way to upgrade a plain text connection to an encrypted (TLS or SSL) connection instead of using a separate port for encrypted communication.

http://en.wikipedia.org/wiki/STARTTLS

The smtp server is saying it won't accept plain text connections.

Answer 2

Use EHLO instead of HELO. This will start 250-STARTTLS.

Answer 3

You basicaly just need to specify that you're using TLS.