Hi, I'm Diane and I'm happy to help you today.
Do you need to know how to connect to the account or how to get the folder list (or both)?
Are you going though classic Outlook or connecting your code directly to web mail?
Please note, this Community primarily provides consumer support, and your question is focused on developement, the new Q&A forums are better suited for these questions. https://learn.microsoft.com/en-us/answers/
Stackoverflow.com is also a great resource for coding help - and they have a lot of the needed code samples already, so you don't need to ask a question.
Unfortunately, moderators are unable to move messages to that forum, so you'll need to repost it.
Let me know how it goes, I'm here to help you further if needed.
-- Diane