Gatsby, I've been lurking a while and must say I agree with all the advice you've gotten. I'd add, however, that if I were to say my piece under these or any circumstances, I would do so face-to-face or in a snail mail card or letter, but not in an email which can take on an exponentially extended life of its own to dozens - hundreds - of unintended recipients with the click of a mouse!
Gardener
"My soul, be satisfied with flowers, With fruit, with weeds even; but gather them In the one garden you may call your own." Cyrano deBergerac