Three Envelope Mockup
The best Envelope Mockup allows you to showcase your front and back envelope designs in a single mockup. Simply use smart object option for the design insertion and use well-named layers for the rest of customizations.
Free

The best Envelop Mockup to display envelope, invitation, greeting card, post card and get a realistic outcome. Inside psd file you can change the artwork of inner side and front of envelop by using smart objects. Background of the mockup is also customizable.