I am on an iMac running El Capitan. I have always used the original Magic Mouse. That mouse is now giving me issues. It has become sticky when moving around but not in every program or application, primarily when mousing over or around in the Gmail message portion of the screen, not after opening an email but selecting one. Because of that I pulled out an old Logitech NX80 mouse from an old Dell laptop. That solved the stickiness problem but it lacks sideways movement the Magic Mouse has. Can anyone recommend an alternative mouse to get? Either bluetooth or one that has a dongle. Maybe bluetooth is part of the issue, I don't know. The old logitech I am now using has a dongle. Thanks in advance.