[pii_email_d66aec8ab3772e6af11b] is a Microsoft Outlook error that can occur while attempting to open mail files and folders. This causes the error message of the Outlook application to appear. The error message will display as:
Error opening. outbox from the domain. Outbox is not set to files.
This issue is displayed to users when sending and receiving mail from Microsoft Outlook. You can tell if this error message is a result of a poor organization of mail files in Outlook or a problem with the mail server that it’s communicating with.