You can configure the sender and recipient details for each form by going to Contact → Edit a form → Mail (horizontal tab).

Make sure the “To” and “From” fields use the same email address.
In the “From” field only, wrap the email address in angle brackets < >.

Example:

To: info@yourdomain.com
From: [your-name] info@yourdomain.com

Refer to the screenshot above for guidance.