How to View all Correspondence Sent Through OnePosting

Click 'Documents' on the top left, then 'Query Message/Envelope Status'.  You can search by document number, email address or postal address.  When you find the message, you can open it by clicking 'View' and it will open in a new window.

You will now see all details relating to the message including the channel through which it was sent and the date it was sent.

If your customer has not received the notification, here are the steps to take.