What's wrong with onsetting transference?

About the topic. My T basically never responds to emails, unless I'm in crisis and I explicitly ask for an answer. Then he'll probably answers with a single sentence just to acknowledge my email and remind me when we meet. It has happened couple of times but I've emailed him many more times.

Recently I have rather called, mainly because he generally answers his phone if I'm calling on a reasonable time and the 5 minutes he is willing to talk to me is usually enough. Also, the calling has become easier over time, in the beginning even the thought of calling generated a lot of extra anxiety in me. Now I have the knowledge that I can trust my T and he believes me that when I do call then I do it because I really need to.