Hi! The password change is a good start. You should also check that your contact methods remain the same here:
https://account.live.com/proofs/manage/additional
After that, close all your open sessions. You will need to log back in to all your devices, but it's safer this way:
https://account.live.com/proofs/manage/additional
After this, please review the next link to see if any apps that you don’t know have access to your account and delete them:
Finally, do this in Outlook from Edge:
Sign in to Outlook.com
Click on the gear icon (Settings) in the upper right corner.
Look for and open Mail settings.
Go to the Rules section and check if there are any rules you didn’t create. If there are any suspicious rules (for example: “forward everything to @.___” or “move everything to Deleted”), delete them immediately.
Also check in Forwarding and IMAP and make sure there are no addresses added. If there is one and it’s not yours, remove the forwarding.