Outlook and Outlook Express have always downloaded everything from multiple accounts into one inbox. I'd set up some folders for the different accounts and rules to divert the mail into those folders.
Surface Pro (2017) vs Surface Pro 4
20 groundbreaking 3D animation technologies coming to Siggraph 2017
iPad Pro 12.9 vs Surface Pro 5
Synology invites you to visit them at Insomnia on 26th – 29th August. Book your tickets now and visit Synology.