Your own SMTP Email Address
Every site created on MarketplaceKit has a default noreply email "email@example.com". Any email sent through their website is sent through this email.
If you want to use your own branded email instead of "firstname.lastname@example.org", you need to use your SMTP service like https://www.mailgun.com/smtp.
You can also contact us and let us know that you'd like to use your domain for emails.