You can order our software via our payment provider: Paddle.com.
Before you purchase DKIM for Exchange Server and IIS SMTP Service, you are recommended to learn more about License Agreement.
AIFEI & AdminSystem Software license is lifetime, but each software license is provided with a software upgrade/support period. Upon expiration you can no longer upgrade the software with your license key. If you want to subscribe one-year software update/support, please contact email@example.com.