I'll leave it, maybe it will be useful to someone.
If you have a problem uploading data from the box.
Then check the following.
0. You must have the appropriate permissions
1. Your contact card must contain
mail@yourmail.com2. Integration with mail has been set up (@yourmail.com and it should work)
3. In the box settings (your box address/admin/shop/settings/notification-email-shop/) in the "Return E-mail address for letters" field, you must specify the email from point 2 of your choice.
4. Check with the hoster "@yourmail.com" the reason why the mail does not work.