Mail Server Woes

[Smiler.]

I use a function to send emails from a PLC (ESMTP using AUTH).

I use Telnet to check the settings are ok.

There used to be a line returned after connecting to the server (using port 25) & typing EHLO which stated:

250-AUTH PLAIN LOGIN


I would then enter AUTH LOGIN & away we went.

Note, it returns 503 auth command used when not advertised


The ISP for my websites/mail servers (not BB provider) has advised me:

"This is the expected outcome as port 25 is now a server to server port by design following the migrations.

You'd need to use port 587 and authenticate with credentials in a secure manner.

Over time, we will slowly stop non-SSL ports being used on servers for customer privacy and security but for the moment, some non-SSL ports do work as normal."


Tried using port 587 - same response.

The ISP said "I suspect something isn't being sent but it's not something we have debugged through telnet as it's not a common method of connecting."

I've spent a few hours trying to resolve this & found some comments suggesting that openSSL is a solution:

openssl s_client -starttls smtp -connect smtp.gmail.com:587


I tried this (replacing the relevant parts with my settings) but it would not operate from the CMD prompt.

Further reading suggested downloading binaries at which point my head was ready to implode.

HELP!