A milestone contains a 'to do' list of items that must be achieved to meet the deadline. If it has not been completed by the due date they change colour to red and reminders are sent out by email. Milestones can also send out warnings before they are due and you can arrange them to nag people if they are ignored.

For businesses running Exchange Server 2000™ milestones can also be made to appear in Outlook™ calendars.