The usual reason for a 0% open rate is having given Zonmaster a "send from" email address that is not registered with Amazon.

To check this go to your stores page on Zonmaster:

1) Go here https://www.zonmaster.com/amazon_stores
2) Click on your stores name

You will be taken to your store's details page on Zonmaster.

You can check the address you've given us by looking at the "Send Email From Address:" value.

Now scroll down to the "About the 'Send From' Email Address" section. 

Here we explain that the address you've given us HAS to be registered in your Seller Central (we also explained this in both text and video during the signup process).In this section we will give you links to the appropriate place in seller central for you to check. Please click the link and go to the amazon Alternate Address page.

If the email you gave us is not authorized to send to Amazon we have been sending to amazon but Amazon will not deliver the emails.

We suggest adding the email you've given us to Seller Central (not changing the address in Zonmaster).

Please note: this address needs to be registered in EVERY marketplace you sell in. We should give you links to all your marketplaces in this section. Please be sure to check them all.