This is why (even as a young person) I never used an email address linked to an ISP. I have always had a Hotmail account (when it first started) and then created a gmail account and now use the hotmail account for spam sign up that I really don't use anymore. I do have an ISP email account and have had it since being a customer of theirs but have never used it.

It is surprising at how many people use an ISP email account and not think of if/when they change providers that they will no longer have access to this.