Once a paid license with a commercial contract, you need to see if the configuration of Office 365 Exchange and look if it's a group or all organization - if is selected all organization, the license button will not appear and will apply to all email in the organization. If you selected groups, the license button will appear, and you then can exclude emails from licenses.
'Manage license assignment with a commercial contract'
- If you select Specific Group:
Create a group in Office 365 or G Suite containing the user mailboxes and/or groups of user mailboxes you wish to protect with CloudGuard SaaS.
Then, in the pop-up, select the option Specific Group and enter the name of the group you created (only one group name may be entered). Only user mailboxes included in that group will be scanned by CloudGuard SaaS.
If the group selected contains more than 500 user mailboxes, CloudGuard SaaS will assign licenses alphabetically (based on the Display Name in Office 365) within the group.
When you select a group, there you can only select 1 group, so when you select a group be sure that there are all the users that you want them to have licenses.