No, mobile keys can only be sent using a mobile phone number.  Email does not offer the same level of security we require to deliver hotel room access, as there is no way to verify identity.  The OpenKey app requires the user to verify their identity by entering a verification code.  This code is requested by the user when they enter their phone number into the app.  If the phone number matches the number entered into OpenKey HOST, the guest will be able to access their mobile key.