Your marketplace sends email notifications to your users for a variety of events. Your marketplace outgoing email address is the email address from which your marketplace emails are sent. The sender email name is the sender name shown by the recipients email client.
A full list of email notifications sent by your marketplace can be found in this article.
The outgoing email address is configured per environment. This means that different environments use different outgoing email addresses.
Your Test and Dev environment outgoing email address is automatically set when you create your account. It cannot be changed.
Your Live environment outgoing email address is automatically generated when you create a Live environment. You can change this to your own custom email address starting from the Pro plan by following these instructions.