If a message reaches the right person but they do not understand its purpose, what should be checked first?

Correct answer: Whether the purpose of the message is stated clearly.

Since the message reached the intended receiver, the first issue to examine is not reach but clarity of purpose. The receiver should be able to identify why the message was sent and what action or response is expected. Medium, colour, and word count matter only if they interfere with clarity; they are not the primary check here.