Subscriptions help you coordinate development with other designers.

You can subscribe to an item to receive e-mail when an event occurs for that item. Events include attribute changed, state change, owner changed, note added, and new revision. You may choose which events to be notified about.

The messages are sent by a Web service via e-mail so you don't need to be using Creo Elements/Direct Drafting or even Creo Elements/Direct Drawing Manager to receive the message.