Examples disclosed herein relate to a method comprising receiving, at a network device, an authentication message intended for a user from an authentication server. The network device may be registered with the authentication server as a source device for the user. The method may also include determining, by the network device, a management device for the user that is the intended recipient of the authentication message. The authentication server is not configured to securely connect to the management device directly. The method may also include transmitting the authentication message from the network device to the determined management device.