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
Helo gmail.com
250 mx.google.com at your service
MAIL FROM: <******@gmail.com>
530 5.7.0 Must issue a STARTTLS command first. h8sm66301168eew.16 - gsmtp

what is STARTTLS command and what do i need to do with it?

Phosphine

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.

Sension

so what are the solutions? – Neurophysiology

@Neurophysiology There are no solutions for this question. You cannot send a mail to that server using netcat because of the encryption requirement. – Sension

well, I had that problem with EC2 and CakePHP and it turned out I had to add ssl:// to the host to make it work. – Neurophysiology

Answer 2

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

Fascinator

Answer 3

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

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