It does seem like therapists change their boundaries on this quite a lot. I had one T that let me email or text however much. She wouldn't necessarily respond but looking back I think it was unhealthy. With current T, I might text her once in between sessions (generally our sessions are every two weeks). This time I texted her twice back to back days. The first letting her know I was in crisis and having suicidal thoughts but that I was safe. The second was in response to her text to me this morning and letting her know today is going better than the past two days. She seems fine with short texts. Though if I texted her all the time I think that would be a problem. She has told me before when I have to call her. Like if I am suicidal and I have a plan and I've already called three people and I'm not feeling better then the next step is calling her. I think it's all about safety.