One user doesn't get email notification after PO has been approved

Hi! Our JDE is E920 Tools 9.2.5.3. We've got a case that one particular user who is responsible for PO entry. She used to receive email notification after the PO she entered has been fully approved. But at some point, probably her name changed after marriage, her email has been changed and she doesn't receive any email notification anymore. We checked her email address is correct from Address Book Who's Who. We also checked the exchange server that it never receives email from JDE that is sending to the new email address. That suggests JDE may not be sending any.