Stuff like spam and junk mail are regulated more that the email service on the server end, not the email app in use. It's a basic server .. client set up. Email messages are managed and maintained within online email servers. Any email app is just a client, it's simply a remote access interface that we interact with. Or in other words, the server does the hard work, the app is just about appearance.
Whichever email app you opt to use is more about its visual user interface. They all are essentially the same as far as capability, the big difference is how they appear and which features they may or may not include in the user settings/menus. If you want to start managing the crap leaking into your mailbox, spend some time setting up filters and actively start marking spam messages as spam. This isn't a binary matter where you flip a switch and it's one or the other, this is an issue where you have to make a conscious effort to 'train' your Outlook account to automatically start putting junk in the Spam folder. Check to confirm the settings in your Outlook account are set up and start using it.