If your account was closed due to lack of activity
To keep your Outlook.com account active you must sign in to the account at least once every 365 days. After 365 days of inactivity, your email will be deleted and cannot be recovered. After 2 years of inactivity, your Microsoft account will be deleted and cannot be recovered.
If your account was closed due to questionable account activity
Outlook.com uses anti-spam technologies to identify questionable accounts. If your account is used to send email that triggers spam filters or send a large quantity of undeliverable email, your Outlook.com email account might be closed.
If you receive an error telling you that your Outlook.com account is closed, you can submit a support request. Go to the email support page. We'll help you recover your account as quickly as possible.
If you receive an error telling you that your account has been temporarily blocked, see Account temporarily blocked
For more help with how to close your account, contact customer support.