Procedure

1. Create or modify an Other (not an Antivirus) policy.
   • For information on creating a new rule, see Adding Policies.
   • For information on modifying an existing rule, see Modifying Existing Policies.
2. Under Web Reputation on the Scanning Conditions screen, select Web Reputation settings.
3. Click Web Reputation Settings.
   The Web Reputation Settings screen appears.
4. Select one of the following security levels.
   • High: Blocks more websites embedded in messages but also increases the risk of false positives. Select High if your users are visiting too many malicious websites.
   • Medium: Blocks an average number of malicious websites. Medium is the default setting because it blocks most web threats while keeping the false positive count low.
   • Low: Blocks fewer websites embedded in messages and reduces the risk of false positives. Select Low if IMSVA is blocking too many legitimate websites.
5. Optional: Select Detect URLs that have not been tested by Trend Micro to increase protection against short-lived websites.

   Note Web pages change frequently, and it is difficult to find data or follow a link after the underlying page is modified. Such websites are usually used as vehicles for transporting malware and carrying out phishing attacks.

6. Select Enable Time-of-Click Protection and click one of the following:
   • Apply to URLs that have not been tested by Trend Micro
   • Apply to URLs marked by Web Reputation Services with smart flags
   • Apply to all URLs

   Note A smart flag is an indicator for rewriting URLs in email messages, which leverages correlation intelligence of Trend Micro Smart Protection Network to detect suspicious and malicious Web threat behaviors.

7. Optional: Select Apply to URLs in digitally signed messages if necessary.

   Note Enabling Time-of-Click Protection for digitally signed messages is not recommended because digital signatures might be destroyed.

8. Select Enable the use of the Web Reputation Approved List to prevent IMSVA from scanning and blocking domains included in the Web Reputation Approved List.
9. Click Save.