It's not everyday I learn about something totally new. I learned today that XMPP uses SRV records in the DNS to correctly determine the highest priority server and port to use. I have now added XMPP DNS service discovery. This improves compatibility with servers across the board and in theory it should also enable connections to Cisco WebEx XMPP servers -- something several people have asked about. I will write back with confirmation.
See debug logs below: