The return address is your incoming mail. In order for the letter to be sent not from the system address firstname.lastname@example.org, but from your address, you need to configure mailfor sending mailings.
You can change the address to which the reply to your letter will be sent. To do this, you need to make changes on the “Settings” tab in the “Return address” field:
Please note, when you make changes in the “Return address” field, the reply will only come to the email address you provided. In order for the answer to come to your account on the GetCourse platform, you need to set up a forwarding from the specified address to the address of the incoming mail in your account: