Unfortunately, there is no automatic way to track email forwards in the SimplyCast system. However, there are a few steps you can set up in order to track forwards through the use of Sonar.
For each email that you want to track the forwards of, create a Sonar link for a URL within the email. Whether this is a blog link, signup form, or landing page, you will need a new Sonar link per email.
Once this link is in the email, you can send it as normal.
Through the use of Sonar, you can track the IP address of anyone that opens that link. Just using the native tracking in the email app allows you to track this for the original recipient, but not anyone they forward the email to.
There are a few caveats to using this method: