When you forward your YVOD-hosted domain email to another non-YVOD account, YVOD does NOT keep a copy of the email message. YVOD has no way to help you with email problems when you forward email.
A much better solution is to configure your email application (Apple Mail, Outlook, Gmail, etc) to check your YVOD account and grab the mail off our servers. YVOD makes weekly backups of all email so if you leave the messages on our server for a week, you will have a backup.
How nice. How sweet. How easy =)