Here in the SaneBox support department we haven't seen any influx of trouble reports from users of MS Exchange hosted email addresses. However, across the wider internet at large we have seen reports that some Exchange based mail users are experiencing OSX Yosemite Mail app crashes. So, we did want to mention it just in case.
This Apple Support Forum post exemplifies the phenomenon. Use of webmail (OWA - Outlook Web App) should be a viable alternative temporarily. Please seek guidance from Apple Support before going forward with the troubleshooting solution mentioned in the forum thread.
SaneBox never interacts directly with your computers, devices, software, or apps. As a cloud-based service, we communicate directly with your mail server. There's no way for SaneBox to affect the email software you have on your computers or devices.
Any time you find the need for a first-hand process of elimination to make sure that SaneBox isn't party to a problem you're having, you can "Pause" your SaneBox account services and then reenable them when ready right from your dashboard: https://www.sanebox.com/dashboard/settings
Please Note: Apple is hard at work with upcoming OSX updates geared towards resolving various bug type problems for Apple Mail in OSX Yosemite. Dec 12th, 2014: developers have been asked to focus on Apple Mail fixes.
If you have any questions or just want to let us know that you are experiencing this sort of trouble with Apple Mail in OSX Yosemite, click here to tell us about it.