I mean, that really depends on how you define server meshing.
Star Citizen is the only MMO I've seen where you can be standing in one server, look at players/objects in a different server (a few feet away) and actually shoot/interact with those objects without noticing any difference.
The only way you can even tell they're in a different server is by keeping an eye on a server identifier using some console commands, and walking/flying over the boundary.
In every other MMO the servers are either completely separate, or there's some sort of loading screen between areas.