After applying rate controls, the Barracuda Email Security Gateway performs analysis on the IP address, applying quarantine, block, encrypt or redirect policies that you configure in the BLOCK/ACCEPT pages.
BLOCK/ACCEPT policies created at the per-domain level do NOT apply to outbound messages. So, for example, navigating to the DOMAINS page, then clicking Manage Domain for a particular domain, then configuring policies on the BLOCK/ACCEPT pages ONLY applies to inbound messages for that domain.
Once the true sender of an outbound email message is identified, the intent of that sender should be determined before accepting the message as valid, or "not spam". The best practice is to know the IP addresses of trusted senders and forwarders of email and define those on the Barracuda Email Security Gateway as "Allowed" by adding them to a whitelist of known good senders. Various methods for discerning "good" senders of email versus spammers are described in this section to help you to quickly configure your Barracuda Email Security Gateway per the needs of your organization.
Barracuda Networks does NOT recommend whitelisting domains because spammers will spoof domain names. When possible, it is recommended to whitelist (Allow) by IP address only.