I need to be able access the messages I've stored in these subfolders, but they're not there. Can anyone help? Thanks.

are you sure they are stored on the server and not moved to your local computer when stored in these folders?

I have the same problem. I have an iPad that syncs with Exchange via OWA. The folders show and I can open them, but only very recent messages are listed. How can I see ALL the messages?

Go to Settings on IPad, then select Mail, Contacts, Calendars.

Select the account, then under "Mail Days to Sync", choose NO LIMIT.

Just tried it and it works. I already had that setting but I needed to check others as well.