Perfunctory, or carried out without a minimum of effort or reflection, is the term I think of whenever I hear a politician or TV anchor after a murder or natural catastrophe, say, “Our hearts ...

Shari Lewis’s pioneering role in children’s television becomes clear in a new film that can be perfunctory about her life.

Read a perfunctory email. Workers often think the most productive approach when confronted with mind-numbing tasks is to try to fight off the boredom and persist in completing them in one sitting.

You can reply with equally perfunctory well-wishes, thereby managing your expectations of the friendship and avoiding resentment. You can, as you suggested, let it peter out by not replying.