1) Go to https://portal.office.com/. Sign in with your Outlook account.
2) Click on Mail. Outlook will open up.
3) Click on "New".
4) Click on "Add-Ins".
5) Select Mosspaper's add-in.
6) Click on "Get free account".
7) Fill out the fields for a new account. Click on sign up.
To view your Mosspaper account, go to https://app.mosspaper.com/accounts/login/ and log into your account.