If you are using an account that has had MAPI connected to it in the last 2-3 weeks before this update, we've been providing guidance to clear your Outlook profile and MAPI connectivity data from the user's connectivity page. 

You can use this guide to help clear out older information,

We've made some fixes that clear up some syncing issues but some older data from our other beta releases have polluted some of the sync files for MAPI, heading towards our release it would be good to start with a clean slate in some cases. If your still having issues still, keep us posted and we'll reach out.

This is a huge concern of ours.

Doing this to every device is a time consuming task and a very frustrating issue for clients.

We have now seen this many times and we are concerned about this going forward.

Is this something that will be resolved once for all or can we expect this same problem in upcoming builds? 

Fully aware of that.

We have used smartermail for over a decade, its not the first beta.

But this is a production ready beta and we continue to see updates break previous fixes.

Im concerned that updates AFTER this goes live will require the same since we have never seen this in the past.