Abstract: A method of handling e-mail messages and a server for performing the method are disclosed. In the method comprises, receiving an e-mail message from a sender for delivery to a recipient, and delivering the message if the sender is included in a list of senders authorised for communication with the recipient. Otherwise, the method parses a destination e-mail address in the message to extract from it an authorisation code and if the authorisation code is an acceptable code, adding the sender to the list of senders authorised for communication with the recipient and delivering the message. In the method, any authorisation code has a validity that us limited for a specific length of time.