When you send an email, it usually has two addresses that indicate its origin. One is displayed to the recipient, the other one – the MAIL FROM address – is more of a technical nature to indicate the email's source.
The MAIL FROM address is often also referred to as "return path", "bounce address", or "envelope sender".
Newsletters sent from Magic Pages always display the email address to the recipient that you set in Ghost itself. However, currently, the MAIL FROM address is using an amazonses.com domain, as this is the email provider Magic Pages uses under the hood.
To give you more control over the emails you send, the implementation of a custom MAIL FROM domain is the logical next step. The technical aspects aren't too trivial, so this might still need a bit of time.
If you have any feedback or input on this, please use the comments below or send an email to help@magicpages.co.