It will make it easier for us to help you if you make a jsFiddle. Then, we can see what your page looks like instead of reading your HTML and constructing the page in our minds... As well, then we can make changes and post a URL to the changed Fiddle.
I'm afraid I'm struggling to understand what it is you are trying to do. I don't know what an "exit tab" is. Nor do I understand what you are saying about scrolling. "Scroll down the page and try to exit"? I don't understand what that means.
It will help to see the page.
Realize that mousemove will fire continuously so long as the mouse pointer is moving. So, your code as you have it now will repeatedly fire. You should stop listening for mousemove once you've satisfied the condition.
$(document).off('mousemove');
Would appreciate the help with getting the code to popup regardless if the user is at the top of the page or bottom.
I'm not sure what you mean by that.
Is the a site you can point us to that does something similar to what you want?
Are you trying to see if the mouse is moving off of the browser content window? If so, why not also left/right as well as top/bottom?
As written, the code doesn't care what direction the mouse movement is in - just that it is moving within 5 pixels of the top.
Realize that this will be of no use for touchscreen devices. There is no mouse pointer. You could support touch events, but few users would slide their finger off of the page. They would just tap on something else.
Personally, I find sites that try to force a popup on me as a last-ditch attempt at attention before the user leaves quite annoying! ;)
In any case, if I wanted to implement this, I would seek out a plugin, and leverage the work that others have already done.