The staging branch uses a copy of your production database, so it has information about your customers. Testing the staging branch can send emails to real customers. This is why emails are only activated on production branches. The staging and development branches do not send real emails. If you want to test the email system before deploying any feature into production, you can use the mail catcher where you can see the list of all outgoing emails. The mail catcher will be available in the staging and development branches.

The mail catcher will display an email with the source and any attachments, as shown in the following screenshot: