AWS requires from addresses to be validated but the EmailNotificationSender for Workflow is hardcoded to use email@example.com which cannot be validated.
This is not like the behavior in other portlets where the from address is configurable and therefore can be easily made to work in a cloud environment:
0) Configure an SMTP server in Server Administration.
1) Turn up logging on com.liferay.util.mail.MailEngine to DEBUG via Server Administration. This will allow the from address to be seen in the logs.
2) Enable workflow on a Web Content folder using the stock Single Approver workflow.
3) Add a Web Content to this folder and submit for publication.
Expected Result: The notification email is sent using a configured from name and address by setting these portal properties:
Actual Results: The name is hardcoded to Liferay Portal Workflow Notifications and the address is hardcoded to firstname.lastname@example.org.