Probably everyone has a free email address - someone more than one. And many of us has some very old one, that has become the "official one", the one used to register in our main interests service sites (electricity, phone, ISP provider, social networks,...) and the one all our friends use to communicate with us.
And many people are recently facing some "little problem", in handling all communications using web mail. Yes, web mail.
Noy many providers give free access to your accounts using POP3 or IMAP (the way you have to use to access using Outlook or ThunderBird) - you have to pay for that.
In my opinion, that is NOT a feature you can miss - and there are providers that give it for free (first of all GMail).
So, if that's your case, consider moving all your email to another service, with free POP3/IMAP access.
If you are concerned about your old email, you can download it once using Freepops, then start using your new email account, changing with some patience your registration details in the service sites you regularly use, keeping an eye sometimes at your old webmail account.
After some time, DELETE it. That way you'll be sure no one will keep sending emails there! ;)