SMTP Authentication is setup in Messaging Gateway but testing is failing
You can test if SMTP Authentication is working on Messaging Gateway with these steps:
(NOTE: Before you begin you will need to base64 encode your test username and password. There are multiple tools/websites that can do this. Use caution in providing security credentials to unknown third party websites)
Run command, "telnet -b 127.0.0.1 <IP of SMG> 587" (where <IP of SMG> is replaced by the IP configured in the Authentication tab)
It will return a 220 banner including the name of your Messaging Gateway.
Run command, "EHLO example.com"
It will return the SMTP verbs offered by Messaging Gateway. AUTH LOGIN should be in the list.
Run command, "AUTH LOGIN"
It will return, "334 VXNlcm5hbWU6" (This is a base64 encoded string asking you for your username) Paste the base64 encoded username you created earlier.
It will return "334 UGFzc3dvcmQ6" (Again this is a base64 encoded string now asking for your password) Paste the base64 encoded password you created.
It will return, "235 2.0.0 Authed. Go on."
Run command, "mail from: <sender email address>"
It will return, "250 2.0.0 MAIL FROM accepted"
Run command "rcpt to: <recipient email address>"
It will return, "250 2.0.0 RCPT TO accepted"
Run command, "data"
Type, "Subject: Testing SMTP Auth" (Press enter twice here)
Type, "Test email"
It will return, "250 2.0.0 OK"
Run command, "quit"
It will return, "221 2.3.0 server.example.com closing connection"