Store mail not being sent most of the time is simple user error but some times can be a server issue. Try the following to figure out where mail delivery is failing.
You’d be surprised but most often it’s a typo in the admin email address double check the admin email address.
Second most common is spam filtering be sure to check your spam folder
If that doesn’t resolve the issue install the following plugin to check that mail is being delivered by WordPress
WordPress Email Log http://wordpress.org/plugins/email-log/
This will log every message sent by your site.
If you see the emails in this log then everything on the WordPress / Store side is working. You should contact your hosting provider for further assistance. It’s possible your mail server isn’t working or you’ve hit a sending limit.
If you don’t see mail in this log you will want to follow our troubleshooting guide. Conflict and Compatibility Testing