To change the size of the product image which is send in the back-in-stock or sign-up email to your customer you have to go to the Crivex Dashboard. Click in the menu on Email Templates and scroll down until you reach the editor.
1. Click on the button (SOURCE CODE) and scroll down to the bottom. You'll now see the text in HTML.
2. Change the value of the width of the image to the value you desire. (100px is standard).
3. Save the page and send yourself a message to check the result!