If you have email addresses you suspect are being blocked by the spam filter, this should allow them to come through.
Log into the Barracuda spam filter at:
https://control.maclaboratory.net (click button for password if you don't have one)
Then click "Preferences"
Then click the "Whitelist/Blocklist tab.
Enter the email address in the "Allowed Email Addresses and Domains (Whitelist)" section and use the "Add" button to add it to the list.