Hi Kelsey,
If I understand correctly:
You want new users to submit new posts for review before publishing as well as restrict them from accessing inbox.
In short, you can set up rules for both, post creation and inbox responses, as well in conjunction with custom roles and workspaces you can set up tailored work environments for your company users.
I would like to recommend having a look at our Approvals documentation for approval rules and how to create them, as well as custom roles and workspaces if you like to restrict access for your company users.
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