Emails in FusionReactor can be configured on the email settings page.
Here you define the SMTP server to be used by FusionReactor when sending out emails such as Enterprise Dashboard alerts, Daily reports and Crash Protection.
Each instance must be configured separately.
Once you have configured the mail server, you can send a test email on the settings page. If the email sending fails for any reason you will see a red error banner, however, there will be no context to the error on the page itself.
To see the error returned, you can go to the FusionReactor logs under the FusionReactor menu (top left). Any error contacting the SMTP server, or any error returned from the server will be logged to the reactor.log file.