For customers not using the Azure Sync
For customers NOT using the Azure Sync, mailbox population and license management is manually managed manually by the MSP.
You can edit the number of licenses for a customer from the customers page, by clicking the pencil icon.

The below table explains which roles require a paid license.
Role | Paid License |
---|---|
User | Yes |
Administrator | Yes |
Built-in-administrator | No |
Functional Address (Shared mailboxes / distribution lists) | No |