Is sending a ringtone to a mobile phone via the internet to a friend considered a sin or an iniquity?

If the ringtone is musical, then it is forbidden to send it to others via the internet or otherwise, because it falls under cooperating in sin and spreading evil, as Allah Almighty says: "And do not cooperate in sin and aggression. And fear Allah; indeed, Allah is severe in penalty." The prohibition of music is established by evidence, including the saying of the Prophet, peace and blessings be upon him: "There will be among my Ummah people who will consider unlawful sexual intercourse, silk, wine, and musical instruments as lawful."