Hi Paty! 

You can select which inboxes have access to a message template using the Make available for any inbox setting as shown in Step 5 of the From Settings section above. To use the message template, teammates need to first have access to the inbox, and can then set the appropriate channel in the From field of the composer to use the available message templates of that inbox.

However, if a teammate has the Shared message templates and folders permission on their account, they can view all shared message templates in Company settings, even if they don’t have access to the selected inboxes. To prevent users from viewing all shared message templates in Company settings, you can remove this permission by using a custom role.

Hope this helps!