Email problems

Hi

A client of mine asked me to check why he doesn’t get any notification emails from eShop.

I put the shop in test mode and made a test order, did not get any emails. He hasnt gotten any mails for a few months.

I took a look at his orders, since the 20th of december 2015 all orders appear twice.. and they are all marked Processing in the Shipped tab except for one, which has a transaction ID. The test order I made (shop in test mode) also appears twice. He can see payments in the bank.

The site is on a multisite network, only one site uses eShop though. What is the best practice to debug this?

https://wordpress.org/plugins/eshop/