Set up a field where an email address can be entered to be notified as a record is processed.
Sometimes someone other than the reporter wants to be kept up to date about an issue or enhancement. Tracker has an "Unregistered Email Address" field that can be used for saving an email address within a record.
Email notification rules can be set to notify this email address by selecting <Unregistered User>.
For step-by-step instructions for setting this up, check out the Per-Record Email Address Knowledge Base Article.