The reaction was tepid when I posted this to r/selfhosted too, so I suppose "self-hosting" carries a sense of doing something from start to finish, and by that

The reaction was tepid when I posted this to r/selfhosted too, so I suppose "self-hosting" carries a sense of doing something from start to finish, and by that standard you're right. I just used it to mean: the original mailbox is on my server, and even if I swap the cloud backend or move to a fully self-hosted setup, I don't have to change any settings in my mail clients. And I get what you were hoping for. If you clicked expecting some clever way of hosting without ports and got something else, that's fair enough.