MIME type for wpress file type

Howdy,

I am planning to use EDD to sell a site using AIOWPM and would like to know what MIME type to use so that the .wpress file can be uploaded to the WP Media library AND that the subsequent download is valid and not corrupt.

I am using this snippet to allow the upload, but the resulting download shows as corrupt when attempting to import via AIOWPM:

function my_myme_types($mime_types){
    $mime_types['wpress'] = 'text/html'; //Adding wpress extension
    return $mime_types;
}
add_filter('upload_mimes', 'my_myme_types', 1, 1);

I know that I can ZIP it, but that would mean one more step for the customer to perform and as these are “beginners”, I would like to keep it as simple as possible ??

Cheers!
Lyle