While searching within your own Archive Manager mailbox, you see messages that were not sent to you or sent from you. Searching for the Subject of the message in your Outlook profile finds an Undeliverable 'System' message for that email.
Exchange is configured to deliver all Undeliverable messages to this mailbox. Archive Manager processes this message in the Archive Manager database with the 'To' and 'From' field of the original sender.
This is by design.
Ignore the messages or configure Exchange to send the Undeliverable messages to a different account not being processed by Archive Manager.