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Deem integrates with Microsoft Exchange 2003, 2007, 2010, and 2013, 2013 and 2016 using both forms-based and standard login authentication. It requires an Outlook Web Access (OWA) server. Travel and other services integrate with Exchange by logging in as a limited rights delegate account through the OWA interface using WebDav (Web-based Distributed Authoring and Versioning) over the SSL protocol, or using Exchange Web Services. As a result, calendar events are automatically added to the user's calendar as the user books travel, and contact information appears for quickly selecting an invitee or recipient of a service.
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A mechanism is in place that makes three additional attempts to write to the user's calendar. If there is a failure, the system calculates the delay between the moment of failure and the start time for the event. If this delay is greater than 36 hours, a retry is scheduled for 24 hours after the moment of failure. If the delay is less than or equal to 36 hours, the retry is scheduled for half of the difference between the moment of failure and the start time for the event, up to a maximum of 18 hours after the moment of failure. If the retry fails, the system calculates the delay between the moment of the retry failure and the start time for the event, and uses the same algorithm to schedule another retry. If the second retry fails, the system uses the same calculation and algorithm to schedule a third retry. Each actual retry occurs soon after the schedule for the retry.