I'll chime in here as I've seen this issue for 4 years, and Intuit has done ZERO that I can tell to fix this issue. They quickly blame Microsoft updates but fail to point out that their code is fragile. Case in point, you only need to look in add/remove programs to see that they load 5 versions of Microsoft Visual C++ Redistributable, dating back to 2008! 

What is Visual C++ Redistributable? It's a package that installs run-time components of Visual C++ libraries. These components are required to run C++ applications developed using Visual Studio and link dynamically to Visual C++ libraries. In short, one possible reason 5 versions are installed is that Intuit is attempting to support a significant amount of legacy code dependent on outdated and/or no longer maintained software libraries built by Intuit or another third party. The dependency on legacy libraries, whether specific to C++ or other development frameworks used by Inuit can create any number of negative user experiences...this email issue may just be one.

My company has over 18 years of experience as a QuickBooks Enterprise customer, we are currently on Version 23 (latest release), on a high performance server, with 10 users working from PCs that far exceed the recommended requirements, and we still see this issue off and-on, and each time the fix...or at least the supposed fix...is different. We have never been able to tie our issues to any MS updates; however, its always a possibility.

Lastly, current generation applications should not need to have repair tool run weekly! Intuit simply needs to do better! The support techs are not the issue, they can only work with what script leadership provides them. This is software engineering issue!