The first thing you must configure in Digi Contact is the Recipient email field. You will receive emails from the module on this main email address.
Optionally, you can enter another email address in BCC email field. A hidden copy of the email will be sent on this secondary email address.
Then by From name field, you can choose a name to be displayed on email sent to the users. For example, you can write your website name or your brand name.
Finally, by From email field, you can choose an email address to be displayed on email sent to the users. It can be a real or fake email address, anyway, it can be different from main Joomla email address and from recipient email address.