The email render test space is potentially shrinking a bit, after Litmus having been acquired by Validity earlier this year, and a few folks have asked me if I knew of any other vendors in this space.The main players in that "render testing" space, in my best recollection, have always been Litmus, Email on Acid, and also, Inbox Monster. And Validity itself. So those are the primary platforms/vendors that provide email render testing, and I know lots of folks that use each of them. (Customer.i...
