It's unfortunate that the connected accounts sync feature has now been removed from all Outlook.com versions. It should be reenabled/rethought using Oauth/Modern Auth and Imap/Pop functionality rather than just removed. Among major web-based providers, Gmail and Yahoo both offer some form of email sync/import.
It used pop and IMAP, Low usage, high support requests, and other issues figured into the removal. Users already using it will be able to keep using it - but for how long, who knows. .
