Approval workflow is configured, but when the manager approves the request via email (OWA or Outlook add-in) the approval does not get processed by the service and the requests remains pending (Change History).
The following event can then be seeing in the logs:
“Active Roles Administration Service encountered a problem when processing approval response received via e-mail.
Exchange Web Services address: https://web.contoso.com/ews/exchange.asmx
Active Roles mailbox: ARS-Mailbox
Approval task: 1-332129-2
Sender of approval response cannot be identified from the response message.”
This is caused by an email id being referenced in multiple user objects. I.e.: the same email address listed on different user accounts. This includes user accounts in different managed domains.
This is not a supported use-case in the approval flow, as it leads to an ambiguity.
Make sure that all approvers involved in the approval process hold a unique email address (email id).