Symptoms
Issue scenario depicted as following:-
Destination user: User A (usera@email.com), User B (userb@email.com), User ABC (userabc@email.com)
TO: emailTo (usera@email.com userb@email.com)
CC: userc@email.com
User A will receive total 3 emails.
Diagnoses
This issue only happen to email escalation at Event level. As a workaround, we configure the escalation at Activity level instead. From end user perspective, there wouldn't be any differences since the existing Event level escalation is set for Client Event
Resolution
Workaround applied. Logged as product issue to be fixed in future release.