The invention relates to a method for integrating services in a calendar application via the meeting request functionality of calendar programs comprising: initiating one or multiple services, wherein the initiation may involve the transmission of calendar event information from the calendar application to the service, the service requests being sent as meeting request e-mails to one or more service e-mail addresses, each service e-mail address representing a service, receiving the update requests generated by the one or multiple services, the update requests being meeting request response e-mails or one or multiple second meeting request e-mails processing the received update requests, and updating the calendar application.