An ex-T was a MFT, she allowed me to write her once a year to update her. I did it for 10 years, but sadly the last year she didn't respond But I figured enough time had passed to let her go. Current T will allow me to contact her whenever I "need" to until she moves, retires, or dies. Once she retires, I can contact her a couple times a year for updates, and see her maybe once a year. However, she's made it clear that we can never be friends. She feels the boundaries would get too muddy and one or both of us will get hurt.