A user has locked themselves out of their Symantec Email Quarantine account, and needs to be unlocked.
Environment
Email Security.cloud
Resolution
Follow these instructions in order to unlock an account:
Login to https://clients.messagelabs.com using the primary username for your organization's account or an account with the appropriate level of permissions.
Navigate to Dashboard > Services > User Quarantine.
On the Quarantine Settings page, go to the "Password Controls" section.
Under Unlock passwords section, click the "Search" button.
This will pull and show all accounts that are currently locked.
Click on the locked account and then click "Unlock" to unlock and account.
Go to the login page provisioned for your account. CAUTION: DO NOT try to login right away or the account will be locked out again.