[Erwyn]

It's not about receiving. Receiving is the easy part. It is about the delivery of your own mail.

> you stop giving money to your mail host and get a different one.

I was entertaining the "host your own mail server" thought, I agree that if you don't host it yourself then you can change your provider if it fails you.

[immibis]

Who needs the transmission more - the sender, or the recipient?

Much of the time, when it's for signup verification, especially for a free service, they just write "don't use @live.microsoft.com" underneath the email address box. The user wants to be signed up for the service more than the service provider wants a new user, at least by enough to use an alternate email address. Enough cases like this, and the user quits @live.microsoft.com.

[palata]

> if you don't host it yourself then you can change your provider if it fails you.

Even if you host it yourself :-). The key is to own your domain.

[Erwyn]

If I recall the domain is not the only issue, IP is also deeply involved or am I wrong?