I've upgraded my HP Envy Ultrabook with preinstalled Windows 8 to Windows 10 about a month ago. All works enough smoothly - except the intrinsic Windows Mail & Calendar apps. They don't sync their contents automatically, even with my main Microsoft account linked to my Outlook.com email!
I tried different mailbox sync settings ("as items arrive", "every 15 minutes", etc.) - nothing helps. I tried to disconnect my local account from Microsoft account, and even created a new user from scratch - no result again.
The auto-sync also does not work for other mail accounts, not only for Outlook.com. Sometimes I even get the following error when trying to sync manually:
It seems, the problem is in a system service that should sync all personal data from my Microsoft account automatically. When I open the Mail app, I see the informational message like "Last updated 8 days ago" at the bottom of the message list. When I click the Sync this view toolbox button, the app downloads the fresh contents without problems in the vast majority of cases.
If somebody knows a concrete recipe that may help, write it, please. Don't send me to the following source, it did not help:
The solution with updating the Mail app described here also does not work as I the Store app tells me the Mail app is installed and I have the latest version:
Perhaps, I need to reinstall the app using a PowerShell command or something like that - I do not know...