Applying the Deny Read right on Folder Hierarchies and  Routing Groups reveals the following view to the Helpdesk users ESM – the Administrators view is contrasted in another MMC alongside.

A note of caution:

In order to achieve what I’m describing, Exchange Full Admin Rights are required at minimum. Also, if rights management at this level is totally new, I would suggest reading the article a few times to ensure familiarity with the subject material. Working with the tools discussed is very much like working with the registry, except you could conceivably kill mail for your company. Understand what needs to be accomplished, lab it first to ensure predictable results, and document every step. If you have third party AD management tools that offer auditing, switch these on, and document every step, allowing you to know what to reverse if something breaks. Idly meddling with rights and ticking or UN-ticking things like inheritance at the wrong level, can conceivably break things like mail flow, mail delivery, users opening mailboxes/public folders, etc. Handle with care, document, lab it first, and if possible do the changes with software or a script that you have tested before and offers you a rollback path.