The LEx platform has a built-in messaging system that allows you to communicate directly with other members of the community. To message a buyer/seller about a specific transaction you'll need to get to the order details page (click My Account > My Sales/My Purchases). 




Phone numbers are provided on this screen... 





To send an email, click View... 




You'll find the Send Message button in the buyer/seller information box on the right...





To message a seller before making a purchase, click the orange Ask the seller a question button from the listing details page.