A hybrid user account is an Active Directory account that also has a corresponding Microsoft 365 account.
When creating a new user account in Web Portal you should select user mailbox type on the New User creation wizard:
- No mailbox
- Exchange on-premises
- Exchange remote or Office 365
The third option for Office 365 or Exchange remote mailbox types depends on whether the Microsoft Exchange extension is enabled or not: if this extension is enabled, Exchange remote button will be displayed. If the Microsoft Exchange extension is disabled, you will see Office 365 button.
The default value is No mailbox.
Exchange remote mailboxes
When Exchange remote mailbox is selected, the exchange-related attributes will be created in your on-premise exchange server. So both the Cloud and on-premises environment will have the knowledge that the user has the exchange online mailbox. Exchange extension should be enabled.
Office 365 mailboxes
When Office 365 mailbox is selected, there won't be any flag created in the Active Directory and in the Exchange On-premises server that the user has a mailbox in the Cloud.