Hey @Hafila Hatta ,

To provide "Reopen" and "Close" actions in email notifications such that users can click these links and trigger backend updates in ServiceNow—without logging into the portal. While direct no-login "one-click" REST actions via links are usually avoided due to security risks, ServiceNow best practice is to utilize inbound email actions.

Example:

<a href="mailto:servicedesk@yourcompany.com?subject=Reopen Request INC0012345">
  Reopen
</a>
|
<a href="mailto:servicedesk@yourcompany.com?subject=Close Request INC0012345">
  Close
</a>

When the user clicks the link, their email client opens a reply with the required content.

The inbound action script parses the email, matches the request, and updates the record's state (e.g., sets to "Reopened" or "Closed") on the backend, all without requiring login

Why not to use Direct actions URLs in Email?

• Security: Allowing email links to trigger direct REST updates without authentication is considered unsafe and is not supported out-of-the-box.

• Email reply actions leverage the sender’s address and internal controls to ensure only authorized users update requests.

• Avoid exposing unauthenticated REST endpoints for security reasons.

For more detailed steps, please refer the below

Add Button in Email Notification , Email Reopening Closed Inc , Reopen and Close Inc links in resolved incident email notification 

Thanks,
Bhimashankar H

-------------------------------------------------------------------------------------------------
If my response points you in the right directions, please consider marking it as 'Helpful' & 'Correct'. Thanks!