Lay-out emails broken

Hello, I’m experiencing some issues with this plugin. Especially to get support, I’ve purchased this plugin. Since yesterday, the lay-out of my e-mails is completely broken. If I send some test mails by using the plugin, the result is something very strange. It looks like an HTML version. Is it possible to check this asap please? Because I have webshop and customers receive weird e-mails now.