It didn't take long. SIL's email began with, "I wanted you to know why I returned your gift..." and proceeded to list some of our many transgressions. It concluded with, "if you want to have a relationship with me, you know where I am." It was ugly, manipulative, and classic SIL. It contained language designed to draw a wedge between DH and I and other members of the extended family.
There was a time when an email like this would have tied me up in knots, rendered me sleepless, and ruined my holiday. I am so grateful that DH and I are beyond that now.
There is a lot of power that comes from not caring.