An identity of an email-address utilized by a client device is verified. According to one example, a server receives a request for verifying the identity of the email-address and calculates a first verification token, which is transmitted to the email address to be verified. The first verification token is received by the client device, which in response calculates a second verification token. The second verification token is transmitted to the server. The server verifies the identity of the email-address by verifying that the first and second verification tokens are identical. Other examples are disclosed.