Is it permissible to publish a message that includes specific formulas for praying upon the Prophet, peace and blessings be upon him, along with mentioning the benefits and rewards for those who publish it, and a supplication for provision and health for those who send it?

Undoubtedly, sending blessings upon the Prophet—peace be upon him—contains much good and great reward, for he—peace be upon him—said: "Whoever sends blessings upon me once, Allah will send blessings upon him tenfold." However, one should not contrive a formula not mentioned in the texts. Furthermore, the attainment of reward merely by sending such messages depends on a legal proof that has not been received. Therefore, it is better not to send such messages, and instead, to focus on sending hadiths about the virtue of sending blessings upon the Prophet—peace be upon him—to remind people and encourage them to do so.