Symptoms

Issue:
None of the notification mails for smart actions was working. No notification was sent to the user notifying them that there is a smart action / event pending on their worklist.
 

Diagnoses

Diagnosis:
We firstly confirmed what the issue is and how this should be setup.
We then found they are moving their smart action mailbox to an office 365 account.
We validated the connection strings using the connection string editor and ensured they were pointing to the office 365 user and offices 365 EWS url.
We then reran the configuration wizard for black pearl and validated that all the smart action details are set to office 365 account and that the exchange integration was enabled.
After the notifications was fixed we found that the smart action mails did not work and was not processed after received.
 

Resolution

Resolution:
We applied EWS debug and found that the email account of the local k2 service account was pointing to the wrong email.
We then changed the email address on the user to match the email we receive from the smart action mails.
After this was done k2 was able to resolve the k2 user when receiving a smart action mail.