User Mailboxes and Shared Mailboxes
Exchange Server supports user mailboxes and shared mailboxes. User mailboxes are used by people who log in to their mailbox to send and receive e-mail. Shared mailboxes do not have an active user account, but represent a department, group, or service like OpenEFT or BillFiler. Shared mailboxes have a disabled Active Directory account and do not need an Exchange client access license or an Exchange Online license.
Users must be granted permissions to interact with a shared mailbox. Permissions are granted to allow users to:
- Access a shared mailbox and work with the items in the shared mailbox.
- Impersonate the shared mailbox and send email as that mailbox.
- Send email on behalf of a shared mailbox.
Access normally works without a problem in a most Exchange environments, but things can be different and not work as you expect.
Granting Send As Permission
The Send As permission is not a mailbox permission. Instead, it is an Active Directory permission.