we had an internet service outage the other day and once the issue was resolved, workflow mailer sen

"You earlier received the notification shown below. That notification is now closed, and no longer requires your response. You may simply delete it along with this message."

The message body included the buyer's name, the email address of the supplier, the date sent and the ID number, along with an attachment of the original PO.

Our suppliers believe this to mean that the PO was cancelled.  What is the reason this message is sent out and how can we stop it?