Symptoms

K2 does not send emails. K2 workspace > Workflow Server > Error Profiles shows the following error:

Send E-mail Event SourceCode.Workflow.Common.EWS: Autodiscover not available and mail cannot be sent. Reconfigure K2 server with valid Exchange settings.

Configuration is set to use Exchange Online.
 

Diagnoses

We double checked the connection string editor values and firewalls and then ran the K2 Setup Manager in repair mode. K2 Setup Manager couldn't identfy the EWS URL on the Exchange server configuration step of the wizard. Debug assemblies were requested from K2 Labs and after applying them the issue was resolved.
 

Resolution

Issue resolved after applying debug assemblies