MobileMe backend using Sun's Java Messaging platform?

It looks like Apple might be employing Sun’s Java Messaging Server (Grid?) for the behind the scenes heavy lifting that enables the new MobileMe functionality.   Performing a telnet to "smtp-mx1.mac.com" on port 25 MacTalk User MacTicks got the following response:

$ telnet smtp-mx1.mac.com 25
Trying 17.148.20.64…
Connected to smtp-mx1.mac.com.
Escape character is ‘^]’.
220 smtpin122.mac.com — Server ESMTP (Sun Java(tm) System Messaging Server 6.3-6.03 (built Mar 14 2008; 32bit))
quit
221 2.3.0 Bye received. Goodbye.

We followed up today with the same request and got the following:

$ telnet smtp-mx1.mac.com 25
Trying 17.148.20.64…
Connected to smtp-mx1.mac.com.
Escape character is ‘^]’.
220 smtpin123.mac.com — Server ESMTP (Sun Java(tm) System Messaging Server 6.3-6.03 (built Mar 14 2008; 32bit))

So it looks like Apple is using Sun for its MobileMe mail platform.  As a background, Sun and Apple have had a long and tumultuous cross-Valley relationship with many technology sharing arrangements.