1. A computer-implemented method for providing messages on a computing device, comprising: retrieving a calendar event associated with a user from a calendar program, the calendar event including information about at least one participant other than the user; determining a user role for the user based on the calendar event, the user role corresponding to at least one of an organizer or an attendee; making a determination that the user role is the attendee of the calendar event but not the organizer; determining a time information corresponding to a time of the calendar event relative to a current time; identifying a rule from a plurality of rules based on the determined user role and the time information, each of the plurality of rules identifying different content for a message; displaying an interface on a display of the computing device, the interface including a selectable feature, that when selected, pre-populates a message to be sent to the at least one participant with content corresponding to the identified rule and information of the calendar event; in response to a user selection of the selectable feature, pre-populating the message with content corresponding to the identified rule and information of the calendar event, wherein pre-populating the message includes (i) pre-populating the message with the organizer of the calendar event as a recipient of the message, and (ii) displaying the message on the display to enable the user to edit the content before the message is transmitted; and transmitting the message to the at least one participant, wherein transmitting the message to the at least one participant includes transmitting the message to the organizer of the calendar event.