Check your spam folder, the account process for hogwarts  live was easy enough when I tried, though the game was a wee bit disappointing since they just hadn't modified a lot of the in game texts from  the Logd originals.

I have heard of a couple of others kicking around, but how accesible they are I don't know.
personally I'd love to play Hogwarts a mystery, but its entirely inaccessible and likely to remain so.

There's a thing called Hogwarts extreme, which is basically a pretty large rp game. You buy your wizarding equipment and then you go to hogwarts and do classes, homework, quidich matches and stuff like that in the form of rp posts. It's not exactly my thing and I don't know if it's even still running, but even things like classes are put up by professors who are themselves players, so if the community is still strong you can check that out.