The 7C’s are:
Correct
Grammar and spelling should be correct, which means accuracy should be there.
Complete
It should contain all the necessary facts or information. There should be a call to action in the conversation. After receiving the message, what are they supposed to do?
Clear
The recipient should not guess the message of the conversation. You should be very clear about what you want to convey.
Concise
Your message should be to the point, short, and simple. It should be explained in the fewest possible words. It should not be lengthy.
Concrete
The recipient should not feel that the message is incomplete. There should be enough, particular, and specific detail.
Coherent
It would be best if you did not deviate from the main objective of your message in the conversation.
Courteous
Your message should sound professional, which means it should be conveyed nicely, respectfully, and not rudely.