Correct manner of sending a "cc:" letter

[Mr. Fabulous]

I'm quite familiar with the usage of the "cc:" at the end of a letter to denote that a copy or copies is/are being sent to another, but when actually sending those copies, does an additional letter of explanation need to accompany the courtesy copy, or just send the copy on its own?

Thank you so much.

[Anglika]

Generally no additional letter is needed.