Abstract: A method comprising: (a) receiving an indication that, having completed composing a message in an instant messaging client application, a sending user has actuated a user interface control for triggering the instant messaging client application to send the message to a recipient user via an instant messaging service; (b) automatically detecting that the recipient user is not currently available via the instant messaging service; (c) in response to said detection, automatically controlling a user interface of the sending user terminal to output a prompt to the sending user asking for confirmation to send the message via email in lieu of the instant messaging service; and (d) in response to said confirmation, sending the message in an email to an email address of the recipient user.