Link Lock
Link Lock provides protection against phishing, business email compromise, and zero day attacks by removing the possibility of a user clicking on a malicious link in an email. Email Protection does this by rewriting all links in every inbound email. Subsequently, when a link is clicked, Email Protection can verify if the destination URL is safe or malicious. If the link is malicious, the user is presented with a block page indicating that there is a security risk.
With Link Lock, links always remain rewritten, even if an email is forwarded. Links are checked in real-time once clicked. Email Protection allows you to exclude URLs from Link Lock by adding them to an allowed URLs list, which can be done at the MSP, customer and domain levels.
Once a Email Protection Plus license is in place, an MSP and can enable or disable Link Lock at the MSP level (default: disabled). Once enabled, Link Lock can also be managed at the customer and domain levels. Each level can apply its own Link Lock settings, with settings being inherited from a higher level by default. If applied, a lower level setting supersedes a higher level setting.
Go to Filtering > Link Lock to enable and configure Link Lock.
Link Lock is an enhancement to Email Protection and is available after the purchase of a Email Protection Plus license. Once a license is in place, an MSP Admin can go to Filtering > Link Lock to enable and configure Link Lock.
This allows a customer or domain admin with "Link Lock Admin" privileges to enable and configure Link Lock for their account. See Link Lock Admin.
Once enabled, Link Lock can be managed at the customer and domain levels. Each level can apply its own Link Lock settings, with settings being inherited from a higher level by default. If applied, a lower level setting supersedes a higher level setting.
Configuring Link Lock
Follow the steps below to configure Link Lock.
- Go to Filtering > Link Lock.
- If Link Lock is not enabled, select Enabled. See Enabling Link Lock.
- Select the Policy Configuration tab and configure your settings:
- Rewrite DKIM-signed mail: Allow Link Lock to rewrite emails with a DKIM signature.
Note: Selecting this option invalidates both DKIM and S/MIME signatures, which may affect scoring on other mail systems.
- Follow redirection links: Select to allow Link Lock to follow redirected URLs (up to a max. of 5). This protects against a legitimate URL redirecting to a malicious URL.
Note: Selecting this option may affect system performance.
- Display a button on the block page to continue to the blocked site: Allow a user to continue to a blocked URL from the block page.
- Show the original website URL on the block page: Display the blocked URL on the block page.
- Show logo on the block page: Displays the image currently being used on the Link Lock block page. Default:
- Use custom logo on the block page: Select Choose File to upload a custom block page image. The following file formats are supported: PNG, JPG and JPEG. Maximum file size is 2048 KB.
- Use custom message on the block page: Select to allow you to add a custom block page header and/or message.
- Click Save Changes.
Adding Link Lock Exemptions
You can create exemptions to exclude URLs from Link Lock by adding them to an allowed URLs list. This can be done at the MSP, customer and domain levels. Follow the steps below to create a Link Lock exemption.
- Go to Filtering > Link Lock and select the Exemptions tab.
- Select Add and the Add Allowed URL window displays.
- Allowed URL: The URL you want to be exempt from Link Lock.
- Comments: Add optional comments about this allowed URL.
- Select Add.