That's the pipe, but the leak is where the pipe meets a black plastic waste pipe outside. Instead of going from the overflow pipe to the larger waste pipe and down to the drain, it spatters down the wall instead.
I recently had a new boiler fitted, in a new location. The condensate pipe runs through the kitchen wall and is then diverted to the drain via some plastic piping. I have noticed that the expelled water leaks down the bricks instead of going down the pipe (some of it at least). The condensate...