@APTOS , Thanks for posting in Q&A.
In general, to use Windows 365 Enterprise, each user must be licensed for Windows 11 Enterprise or Windows 10 Enterprise, Endpoint Manager, and Azure AD P1. Endpoint Manager and Azure AD P1 besides windows 365 license. Here is a link with more details:
https://www.microsoft.com/en-sg/windows-365/faq#coreui-collapsibledrawer-hqbtw10
For outlook access, the user needs mailbox. After confirming with exchange support, I know to let the user enable the mailbox to access outlook. Exchange online license is needed. You can check if this is included in your existing licenses. If not, we need addition license. Here are links about exchange online license for your reference:
https://www.microsoft.com/en-sg/microsoft-365/exchange/compare-microsoft-exchange-online-plans
https://www.microsoft.com/en-sg/microsoft-365/compare-microsoft-365-enterprise-plans
If you have more questions with license, you can contact our licensing support in the following link:
https://learn.microsoft.com/en-us/licensing/licensing-orders-invoices-payments-support
Hope the above information can help.
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