What is the ruling on mentioning the Prophet (peace and blessings be upon him) and sending blessings upon him accompanied by melodies and drumbeats (daf), which are prevalent as mobile phone ringtones? Is this permissible and does it constitute true love for the Prophet?

Listening to musical tunes is Islamically forbidden. The sound of the tambourine (daf) is a matter of scholarly disagreement, with the preponderant opinion being its permissibility. The sign of loving the Prophet, peace and blessings be upon him, is to follow him, love his Sunnah, and read his Ahadith and biography, not merely listening to poems in his praise.