Symantec 10490452 Administration Guide - Page 106

106 Configuring email filtering Managing policy resources If you add Sender Authentication domains, it's best to specify the highest level domain possible, such as example.com, because subdomains of the specified domain will also be tested for compliance. Warning: Authenticating all domains can lead to significant unnecessary processing load. Many domains do not publish an outbound email policy, or publish only an informational policy. Attempting authentication on these domains does not lead to any action, and will use processing resources, at times excessively. Authentication is most effective for domains that publish hard policies that are frequently spoofed in phishing attacks. To enable sender authentication 1 In the Control Center, click Policies > Sender Authentication. 2 Check Enable Sender Authentication. 3 Under Authentication Types, check Sender Policy Framework (SPF), Sender ID, or both. 4 To choose domains to authenticate, click Authenticate only the following domains, or to authenticate all domains, skip to step 6. 5 Click Add, type a domain name, and click Save to add domains to the list. Optionally, you can click on a domain or check the domain and click Edit to edit the spelling of a domain you already added. You can also check a domain and click Delete to delete that entry from the list. 6 Click Authenticate all domains to attempt sender authentication on incoming messages from all domains. 7 If desired, change the default action, or add additional actions. By default, each failed message has the phrase [sender auth failure] prepended to its subject line. 8 Click Save. Managing policy resources The settings under Policy Resources are used in the conditions or actions for policies. Annotating messages Annotations are phrases or paragraphs that are placed at the beginning or end of the body of an email message when you choose the action Add annotation. An