Super frustrating. The only thing that "fixed" the email crashing issue for me was to purchase a new Windows laptop, and do a clean install of QB enterprise. Previously I was running QB Enterprise on a Mac using Parallels, and that seemed to be part of the issue. I luckily had a monitor that does side-by-side display, so I'm still able to run my mac on half the screen and Windows on the other. It's not as elegant as using a virtual machine, but at least the email issue resolved.