In the support dept we often access other people’s mailboxes via OWA by simply putting the mailbox name on the end of the URL.
Eg. http: // myowaserver / exchange / mailboxname
This has worked fine for years, and still works for the majority of mailboxes, however I’ve created some new storage groups and moved some mailboxes around and now it seems we can no longer access these mailboxes in the same way anymore.
Permissions on the mailbox store seem to imply that admins should have access so I’m not sure what the problem is.
By default the administrators are denied access to certain permissions. On the mailbox stores you created go through and remove the deny permissions. You will probably need to disable inherited permissions.