I have several AOL accounts. I've used my master account daily for over 10 years and its just fine. I decided to sign into two other accounts I hardly ever use. (It's literately been six months since I signed into those accounts.)
Anyway they should have new mail and hundreds of saved emails. When I signed into both, I got an AOL message like I was signing in for the very first time. No other mail and all old mail gone. Saved email addresses gone as well.
Do they reset inactive AOL accounts to "new" after long periods of inactivity?
But to answer your question. I do believe most of the places where you make a free email account, if you have not used it after a certain amount of time, it is suspended. They are not, to my knowledge, closed though. You should be able to reinstate them by logging on again.