You will know your account has been locked out if you get an email saying specifically that you have been locked out. If you haven't gotten this email BUT you forgot your password, then simply follow the instructions for automatically resetting your password in this helpdesk article.
If you got an email from the system saying your account has been locked, it is probably because you (or someone else) tried to log into your account with the wrong password too many times. This is a security precaution for your benefit.
If this happens, you can contact your internal ZenDesk administrator to manually reset your account. Or you can email email@example.com for the same.
When the manual reset is complete, you will receive an email with a link that takes you into the application to reset your password and security challenge question. Please note that this link expires 24 hours from when it was issued.