After trying many combinations available online finally a suggested values by a friend works for me. I am able to send MMS from HTC Sensation using Ufone network.
I am attaching screenshot of my settings. The difference I found is copying the same values of MMS Proxy and MMS Port in Proxy and Port. And I changed MMS Protocol same that is set in GPRS APN settings.

Set these values and restart your phone. And you are all good to send MMS.