The good news is that you will soon have excellent spam filtering and a host of wonderful services provided by world class email providers. That is because the bad news is ~~~ you will have to change your email address.
As a former customer, your email service should have been deleted completely 90 days after you left. VM are gradually finding these orphan accounts and deleting them without warning.
My advice to you is to set up an alternative email address NOW. Preferably with a non-ISP provider. Backup all your existing emails using your old password, and start notifying all your contacts of your new address in order of importance to you. Set up forwarding if you can. If you do not have VM web mail access, you will have to re-build your contact list.
But the hammer will drop and you don't want to be left wondering what to do.