How can we refer to the polite phrase used at the beginning of a letter (email in my specific context)?
For example, we may start our letter:
Dear Bob, I hope that you're well and had a nice weekend.
If we want to make reference to the line
I hope that you're well and had a nice weekend
in such a way that we could say:
I often wonder how to begin a letter of bad news, but my [interjection] stands genuine non the less
The term "interjection" doesn't seem like a good fit here. Is there a word that describes the polite phrases we often use to begin our letters?