Configuring preferences and options in Outlook.com
Simon unfortunately Microsoft's Outlook team does not care about the users. It's been years that they have continually made it worse.
Best possible solution for now might be to add a filter rule to filter those daily emails to spam at least as someone else has pointed out.
As for Microsoft ever fixing the synced emails in Outlook. I think I have a better chance at winning the lottery. And I buy a lottery ticket once a year.