When creating a Signature Workflow, the creator has the option to decide whether a reviewer will be notified by email. Follow these steps to turn this feature on:

1. Navigate to the Manage > Signature Workflows page.
2. Select the respective workflow to edit.
3. Click on the Signature 2 or any tab(s) after Signature 1.
4. In the Reviewers section, choose Options for the selected reviewers.
5. Check the box in front of Send an e-mail to them when they are requested to review an entry.
6. Save changes.