My T doesn't do texting or emailing about anything other than scheduling appointments. There's been a little bit of flexibility there where he's asked me how I'm doing when scheduling appointment stuff when I was having a particularly hard time but I don't like that because I don't know how to respond or what the boundaries are. If I felt like I could text him when I was struggling then I'd constantly wrestle with that decision, but since it's not an option I don't have to decide. (He has said to contact him if things are bad and I need to get in to see him before my next scheduled appointment)

I have written letters though. Quite a few that I never planned to let him read and were just cathartic, and a few that I had him read at the beginning of sessions because it was stuff I needed to talk about but couldn't bring myself to actually say out loud. That's been really helpful.