Answer

1. Ensure that your Email Alert setting is configured. For more information, see Alerts and Subscriptions in Tableau Help. 
2. Stop Tableau Server. For more information, see tabadmin stop in Tableau Help.
3. At the command prompt, type tabadmin start to re-start Tableau Server.
   You will receive an email alert if the settings have been configured correctly.

Additional Information

• The email account being used to send the email alert cannot be configured for SSL; SMTP accounts configured with SSL are not supported.
• Three processes that trigger an email alert include the Gateway, Data Engine, and Repository processes.
• To voice your support for the inclusion of a test email feature in a future product release, add your vote to the following Community Idea: Ability to test email alert.