The person who reads the letter is not the "corporation", so that could be considered publication. But, since there are unlikely to be damages for such a statement, I think it unlikely you would be sued. It is when statements are widely publicized that a corporation suffers damages and, even if they do not, they will sometimes sue to remove the statement. (aka SLAPP)
But, if you want a specific, legal, answer to your question if this is on a test, "no".

