Exchange Integration
The K2 Setup Manager uses Exchange Autodiscover to populate the Exchange server settings. If Autodiscover is not enabled on the Exchange server, you must manually configure the settings. We recommend that Autodiscover be available in your environment before installation.
K2 uses Autodiscover before making a call to Exchange to query an available Exchange server. This allows K2 to continue functioning if a single Exchange server is offline.
The configured account, typically the K2 service account’s, is used for the discovery process. Using the Autodiscover service to find the most appropriate URL for the specified user's mailbox instead of using a hard-coded EWS URL means that your workflow always uses the correct EWS URL for that particular mailbox. Autodiscover determines the best endpoint for a particular user (the endpoint that is closest to the user's mailbox server).
For more information see the following KB articles:
Understanding the Exchange Integration changes in K2 4.6
How To: Working with K2 Exchange Integration