Besides being able to manually whitelist or blacklist an address for the entire domain, Administrators can also manage the automatic whitelist. The automatic whitelist is a domain-wide whitelist built from the e-mail sending patterns of all your users. It ensures that communication with trusted recipients always goes through without being filtered.
Notice that the best way to add whitelist records is using the Spam reports, as it automatically delivers the e-mail and adds sender to your whitelist. Our system uses the Sender instead of the From in the e-mail header, both for blacklist and whitelist, which is automatically done if you authorize e-mails through spam reports. If you enter an e-mail address manually to your black or whitelist and notice it doesn't work, check the e-mail header and look for the X-Barracuda-Envelope-From: field, which should be used. Yet another possibility is that the sender might change each time you receive a certain e-mail. In this case, you can use Rules to delete undesired messages, based on part of the From header address or subject.