I love it when I get personal emails from providers that I feel like I have connection with.
If I feel like I am being hounded, then not so much, I'd put a stop to that. If I feel like it's a "canned" bulk email that went to a lot of people, then I just delete it but it doesn't bother me. Calls and texts... not so much, I wouldn't like that. If our meeting didn't go very well, and it seemed obvious we just didn't connect, that make me more inclined to think of it as a the AMT machine you spoke of.
I think there are two very different kinds of hobbyists, and this difference shows a LOT on the boards here...
For some this is just some playtime on the side, it's all on the QT, there's no strings of any kind... You settle up at the end of the appointment and the case is closed, the "encounter" has ended and it's on with life. There is *nothing* wrong with this approach, I suspect most hobbyists are in this category.
For others, it's more about the connection, and getting to know an ATF, or a few faves, and developing an ongoing connection that transcends any one appointment. It's mostly "no strings", but there is one tiny, slender string, a mutual promise to cherish the time together, be open and revealing, and hold each other in high regard in our hearts... Connected as real lovers but none of the other trappings...
I am in that second camp, and so, getting a nice thoughtful email from a provider, that I haven't seen yet, or haven't seen in a while, is a nice thing for me... But again, only because (a) I am in that second camp, and (b) I have a secure private email.