The message was redirected to the recipient's primary email address and then delivered to a folder other than the Inbox. ...

The message was redirected to the recipient's primary email address and then delivered to a folder other than the Inbox. If the message can't be found in the Inbox folder of the recipient's primary email address mailbox, the message may have been accidentally deleted or moved to another folder. Therefore, a search of the recipient's mailbox for the message may locate it.