Symptoms
Workflows throw errors that indicate there are email addresses that could not be resolved. Retrying the step works.
The specific error is as follows:
SourceCode.Workflow.Common.EWS: Autodiscover not available and mail cannot be sent. Reconfigure K2 server with valid Exchange settings.
Diagnoses
There was another error in the HostServer logs:
SourceCode.Workflow.Common.EWS: ","0 Mail send failure: EWS URL is not valid. Verify the connection strings are correct. Exception: The request failed. Unable to connect to the remote server
Resolution
We applied a coldfix to all environments that changes the way K2 resolves email addresses. Specifically, it adds a new column to the Identity.Identity table that stores the email address of the user, in this way resolving email addresses is also faster, since traditionally the email address needed to be parsed from the XML in the "Properties" column, which is an expensive query.
This resolved the original bug of the K2 server not being able to resolve the EWS Exchange server.
A different error message was discovered in the Error Profiles, but a new ticket was logged for that.
Refer to TFS _609896
