You have the option to enter an email from address that will appear to the recipient of all emails you send from the platform. It's quick and easy to set up, but you must set up SPF and DKIM records and verify ownership of your sending domains before you can. See the article here on how to do that.
Follow these 3 quick steps
1. Select Emails
2. Tick the Use a custom from email address box
3. Enter the email address you want email recipients to see
Don't forget to Save Settings once you're done
See a separate article here on how to set the send from address on a per send basis.