FutureVault will alert you when you receive a document from an unrecognized email. Before saving the document you need to add this email to your trusted list.
You can added:
1. Manually on Security:
a) Click on your name in the top right corner, then go to: My Account Settings ->Security->Trusted Emails.
b) Click the plus icon, next to the title.
c) Add the email in the gray box, and click the save icon.
2. Automatically in Unfiled:
a) Click in the red message "Unrecognized email address!".
b) A message will be display letting you know that you have never saved a file from that email before. Click on "Trust this Email Address", the red message will disappear and the
email address will be added to the list of Trusted Emails in the Security area.