JReviews uses both Joomla's and WordPress native mailing functions, so if you have a system that allows you to create your own email template in which to wrap emails that already works for you, there's no need to do anything else. Otherwise, if you want to specifically add a template for JReviews emails, continue reading.
If you want to add branding or wrap the JReviews emails specifically in your own template, you can customize the email layout theme files.
To use this feature, you just have to modify the following theme file (and place it in overrides in your custom theme):
If you are using EngageUsers, the Add-on has a separate email layout file found here: