Any time you make changes to Email, Device Security or Wi-Fi settings, a new profile gets sent out to all enrolled devices. If a device is offline or powered off, those settings will read as "out of date." Once a device checks in with Jamf Now and receives the changes, the status will change to "Applied."
While Jamf Now checks in with devices once a day, you can click the "Sync" button at the top of any device record to request a sync ASAP. Once that device connects to the internet, the device will inventory and updated settings will be applied.