Salesforce Task Assignment Notification Emails Cannot Be Customized — Use Salesforce Flow as an Alternative

Why Task Notification Emails Cannot Be Customized

The Task assignment notification email is a system-generated email in Salesforce. It is triggered by the "Send Notification Email" checkbox on Task creation and is not connected to any Email Template in your org. Because the email is generated at the platform level, it cannot be modified through standard Salesforce configuration.

Alternative: Use Salesforce Flow to Send Custom Task Notification Emails

As an alternative to the default system-generated Task notification, you can build a Salesforce Flow (using the Process Builder or Flow Builder) to send a customizable email notification when a Task is created or assigned.
This approach requires:

1. A custom Email Template configured in Salesforce
2. An Email Alert Action that references the template
3. A Process Builder process or Flow triggered by Task creation that calls the Email Alert

Important Notes

• Workflow Rules on Tasks do not support the "Send Email" action. You must use Process Builder or Flow to send custom Task emails.
• If Single Sign-On (SSO) is enabled in the org, users should log in to the org before clicking the email notification link. The link automatically redirects to the org's My Domain URL.