If it's a long enough time ago, you may be able to set up a new email account, re-using the old name. But any mails in the mailbox will be long gone.
That assumes somebody else hasn't grabbed it.
Following on from this, does anyone know what happens to a deleted email address that's over 90 days, but is the main email address for the account? My email address is my log-in for my BT account, but it says I can't use it in creating a new email.