SMM Mr, Mrs, Ms

There is no strict rule about it, but let's NOT use it. It will save time, space, and make text less visually disruptive. 

Correct: The governor of Anambra state informed Sanusi that...

Incorrect: The Governor of Anambra state informed Mr Sanusi that...

 Use if needed to avoid misunderstanding, eg with family members who have the same surname.