Symptoms

When attempting to action tasks via email, the initial email is replied to, but the worklist item never disappears. Items can be actioned from SharePoint / SmartForms without issue.
 

Diagnoses

Issue was discovered to be an error with SmartActions found in a User Task Event. The current configuration for SmartActions was pointing to an incorrect destination.

 

Resolution

To fix this issue do the following:

1. Open K2 Workflow Designer from the artifacts page for the workflow that cannot complete SmartActions.
2. Find the user event that will not complete via email actions.
3. On the Participants wizard of the event, uncheck the option to notify participants when they receive a work item.
4. Finish the wizard.
5. Access the User Task event again.
6. On the participants configuration wizard select to notify participants.
7. Reconfigure the email that gets sent to the user as required.
8. Finish the wizard.
9. Redeploy the workflow.

After completing these steps any emails that are actioned via email should work again as expected.