Targeted Threat Protection - Impersonation Protect - Custom Monitored External Domains

This article contains information on configuring custom-monitored external domains in Mimecast's Impersonation and URL Protect policies, including steps to add, edit, or delete domains to enhance protection against potential threats.

Adding custom external domains allows you to ensure that these domains are included as part of your Targeted Threat Protection subscription. You can also add the following to this list:

• Domains that your organization owns but are not among your Mimecast internal domains.
• Your organization's vendors' domains provide additional protection against messages using a domain name similar to your vendors.

This page describes how to configure the custom domains monitored in Impersonation Protect and URL Protect definitions if the Similar Monitored External Domains option is selected. For Impersonation Protect, this checks the sender's domain against your custom external domains to search for potential threats in messages. For URL Protect, this checks the URL against your custom external domains to search for potential threats in links.

Add Custom Monitored External Domains

To create custom-monitored external domains:

1. Log in to the Mimecast Administration Console.
2. Navigate to Policies | Gateway Policies.
3. From the Definitions drop-down list, select either:

• • • Impersonation Protection
    • URL Protection

4. Click Custom Monitored External Domains. Any existing custom domains are displayed.
5. Click Add Domains. A pop-out panel is displayed.
6. Enter up to 1000 domains in the Domains field, one per line.
7. Add any Comments up to 50 characters.
8. Click Next. The new domains are listed. If there are errors, either:

• • • Delete the domains using the trash can icon.
    • Click Back to fix them.

9. Click Add.

Managing Your Custom Monitored External Domains

To edit or delete an individual domain:

1. Log in to the Mimecast Administration Console.
2. Navigate to Policies | Gateway Policies.
3. From the Definitions drop-down list, select either:

• • • Impersonation Protection.
    • URL Protection.

4. Click Custom Monitored External Domains. Any existing custom domains are displayed.
5. Click on a domain. It is displayed in a pop-up panel where you can:

• • • Edit the domain in the Domain field. Click Save to save your edit.
    • Remove the domain by clicking Delete.

      Alternatively, you can click on the three-dot icon to the right of the listed domain and select Edit or Delete from the drop-down menu.

To delete multiple domains:

1. Select the checkboxes to the left of the domains you want to delete.
2. Click on the Delete button in the top menu.

See Also...

• • • Configuring Impersonation Protect Definitions

    • Configuring Impersonation Protect Policies