Abstract: There is disclosed a recommendation server comprising: an input interface configured to receive an indication from a user device of a user behaviour; a recommendation engine configured to compile recommendations for a user; and a processor configured to identify an anomaly between the user behaviour and the compiled recommendations for the user. There is also disclosed a computer-implemented method of generating an enquiry message, the method comprising; monitoring behaviour of a user when engaging with a computer device; determining that the user has engaged with the user device in a particular context in which it is predetermined that the user will respond to the enquiry message; selecting a template from a set of templates; populating the selected template with data relating to the enquiry; and transmitting the enquiry message to the user device based on the populated selected template.