Send Test Email no longer working

A Jazz Team Server that was v6.0.2 and has now been upgraded to 6.0.6 is no longer sending email messages.

I have gone to the "Email Settings" page and tried to "Send Test Email" but it doesn't do anything.
Just seems to hang with a "i - Sending test email" message box.

After several minutes I get a java.net SocketTimeoutException : Read timed out

I looked in the ‘jts.log’ file where the error reported was CRJZS5074E.

Looking at the online guidance notes it seems that my problem is to do with the SMTP Server issues that are result of a change to the mail libraries, starting in version 6.0.3 for Collaborative Lifecycle Management.

I read the suggested article on “IBM Knowledge Center” entitled “Troubleshooting the SMTP server” and as a result of doing that I opened a command prompt and issued the commands :
telnet <smtp-server> 25
and then
EHLO <smtp-server>

There was NOT an entry for ‘AUTH LOGIN’ in the list that was returned.

(I don’t know if this is relevant but ‘AUTH NTLM’ was listed).

If I entered the command AUTH LOGIN the message returned was 504 5.7.4 Unrecognized authentication type.

Any advice on what I need to do next to get email working again would be very welcome.

               Peter