You may have the need to allow external email addresses to send email into your email listener and generate an incident for them.
What you are trying to accomplish is possible by adding the domains you want to receive email from under the 'Trusted Sender Domain' tab within the email configuration.
- Log in under the Administrator role
- Click on Configure Application
- Click on Email Server
- Click on 'Trusted Sender Domain'
- Click on 'New' to add domains you want to receive emails from and generate records for.