I had lots of experiences with excessive emailing, not just with Ts. It was a long-standing bad habit for me, a sort of addiction. I actually did not do it to draw attention so much and did not feel uncomfortable with no response, but the latter is exactly why I think it was unhealthy and addiction-like. It wasn't true interaction and interpersonal engagement a lot of the times, more lengthy monologues and a compulsive desire to express whatever was on my mind. It wasn't a desire/need for support or encouragement. But when people engaged, it reinforced it further. I did this most often as a distraction and avoidance instead of dealing with important things, so it truly was unproductive for me but a habit very difficult to break. I never really meant to push people's boundaries but of course it could be interpreted that way and sometimes I did alienate good people with it. I get their side much better now because I've managed to gave up that habit for the most part and I really don't like when someone bombards me with messages in chain, not respecting the fact that I have a life, I tend to lose my motivation to engage quite quickly and would usually just ignore them unless there is really something important we need to discuss. The lengthy monologues and not even allowing time for the other to participate in meaningful ways actually sometimes remind me of my father. I loved him dearly but his bouts of speaking compulsion was one feature most people did not tolerate well in him, including myself. So I don't like when I do it either because I know how it is to be on the other side. It is not an effective way to elicit response or support, kinda more the opposite, IMO. I guess a T should tolerate it better not not get frustrated, but I imagine they can still get turned off by excess.

Going from never asking for anything to wanting/pushing for too much might be interesting to explore in therapy, but I personally would try not to pick up a habit of the latter too much. It can be really uncomfortable and hard to break. When I first developed my habit, it was originally with a significant other, who welcomed it. But then, when the relationship ended, I kept transferring it to a lot of other people, eventually knowing full well what was going on with me, but still unable to stop for a long time.