9Folders uses a validation system. If multiple devices attempt to use the same "leaked" license key, the key is blacklisted, and the app will revert to trial mode or lock you out.
If you already bought Nine and are being asked for a "license key" on a new device, you usually don't need a code. Just ensure you are logged into the same Google or Apple account you used for the original purchase. The app should automatically recognize your "Pro" status. The Verdict: Is it Worth the Price? Nine Email License Key
Nine (developed by 9Folders Inc.) typically offers a . Once that trial ends, you must purchase a license to continue sending and receiving emails. There are two primary ways the app is licensed: 9Folders uses a validation system