![..//assets/img/kb/email.png](..//assets/img/kb/email.png)
An email notification may be sent to one or more recipients when a CyberKey is not returned to the system after checking it out from a Vault. A "TO" email address must be provided as well as the amount of time elapsed after the key expires. The actual key expiration date and time is calculated from the expiration rules of the mission or mission template used to check out the CyberKey.