How do yu have the "Sort" function set? If you have it set to "Date", by default new messages should appear at the top of the Inbox list. But if you have it also set to "Ascending" they will be at the bottom of the list, and likely out of sight. Or if you have the list set to "Conversation" they might be out of view. If it's not that, did you check the Spam folder? Did the test message you sent show up in the Sent folder?