• Efficiency: Information from some JSON files was moved to a new SBIN file to increase efficiency and add functionality.

So the two items we store in the activity.sbin file are the mailbox sizes (which used to be in the accounts.json) and the last login times (which used to be in the user's settings.json). If they downgrade, this data will be outdated. When they then upgrade back to this version (or a future version) both of those values will still be outdated. The last login time may not be a big deal as most of that is just information that is shown to system/domain admins in the "User Connections" tab. The size part is more important but the Accounts tab has an option where you can "recalculate disk usage" and that value will get fixed.

Last login times will be rectified as users login. If you want it as up to date as possible (when re-upgrading later) without people logging back in first, delete the activity.sbin file from the domain and its ArchiveData folder before re-upgrading. That will make SmarterMail redo the conversion with whatever data is available after running in the downgrade state.