What is the ruling on organizing a competition that relies on sending the largest number of text messages, knowing that participants will receive Ramadan remembrances (adhkar) and sermons immediately upon their subscription?

If mobile phone messages contain invocations (dhikr) and good admonitions, benefiting both the sender and the recipient, and the competition adheres to the Sharia regulations for permissible contests, then there is no harm in participating in it and accepting its prizes. Otherwise, it is forbidden.