Big River stores copies of all emails sent out by the system - transaction receipts, email distributions, invitations, etc.  If a constituent says they did not receive an email they were expecting, or are questioning the content, you can verify the source of the email that as sent with them.

Look up their contact record from the Contacts tab by opening the filter button and entering part of their name or email.

Click the Edit link under the contact name to enter their record.  From there click on the Emails tab:

You will see a list of all emails sent to the constituent.  You can click on the pencil icon next to any email to review its contents in detail:

The Basics tab will show basic information about the email - who it was sent from and to, and when it was sent by the system.  This tab will also show the recipient's most recent action on the email - opening it for example.

The Message tab contains the content of the message sent to the constituent:

At the bottom of the Email view, you have the option to re-send the email to the constituent: