Use the following steps to help debug email server authentication issues.

  • Enter "telnet"
  • Enter "set LOCAL_ECHO"
  • Enter "open 25" (replace with your domain).
  • Enter "HELO"
  • Enter "AUTH LOGIN"

You now need to enter your email and password encoded in BASE64.  For help converting to Base64, click on our conversion tool.  Enter your email, click Encode, copy that value in the telnet session and then press ENTER.  Next, enter your password in the conversion tool, copy that value in the telnet session and press ENTER.

If you have successfully authenticated, the server will return: 235 authenticated.

  • Enter "MAIL FROM [email protected]" (replace [email protected] with your email address).
  • Enter "RCPT TO DestinationEmail" (replace DestinationEmail with the destination email).
  • Enter "DATA"
  • Enter "Subject: Test using telnet"
  • Enter "" (send a blank line to separate the headers from the message body)
  • Enter "This is a test to see if I can SMTP auth from my PC"
  • Enter "." The server should return: 250 Message queued
  • Enter "quit"