You can't unfortunately and it's more likely your password has expired or something.
Go to portal.microsoftonline.com and login to see if this is the case.
If not a little more information would be great.
Do you have federation/dirsync or standard integrated logins
Do you still receive email?
GPOs cannot be used with macs and even OpenDirectory or mcx prefs for Mac can't manage that much in outlook there's limited preference manifests available.
Graham