Re: How to find out if SMTP mailserver supports STARTTLS or (only) SSL/TLS ?

I don't have a good server to test with, but the EHLO command should tell
you what the server offers. I'm not sure if it can tell the difference
between STARTTL and just TLS.

https://nmap.org/nsedoc/scripts/smtp-commands.html

PORT   STATE SERVICE REASON  VERSION
25/tcp open  smtp    syn-ack Microsoft ESMTP 6.0.3790.3959
| smtp-commands: SMTP.domain.com Hello [172.x.x.x], TURN, SIZE, ETRN,
PIPELINING, DSN, ENHANCEDSTATUSCODES, 8bitmime, BINARYMIME, CHUNKING,
VRFY, X-EXPS GSSAPI NTLM LOGIN, X-EXPS=LOGIN, AUTH GSSAPI NTLM LOGIN,
AUTH=LOGIN, X-LINK2STATE, XEXCH50, OK
|_ This server supports the following commands: HELO EHLO STARTTLS
RCPT DATA RSET MAIL QUIT HELP AUTH TURN ETRN BDAT VRFY

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On Sat, Oct 21, 2017 at 1:17 AM, Ben Stover via dev <[email protected]> wrote:

> Assume a (remote) smtp mailserver smtp.foobar.com listens either on port
> 465 or port 587.
>
> How can I find out (with nmap/netcat) if this smtp mailserver supports
> STARTTLS protocol or (only) SSL/TLS?
>
> Or both ?
>
> Thank you
> Ben
>
>
>
>
>
>
>
>
> _______________________________________________
> Sent through the dev mailing list
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