If you customise the top toolbar in EMClient V7 Build 26787.0 and put the “Mark” button up there, EMClient hangs for aprox 5 secs when pressed before it does anything ?. So yes it does work, but its very delayed. Replicated this problem on 2 computers running Windows 10 Latest official build 1607. Ps This also happens with the “Categorize” Button on my other Forum Post.