Check your "View" Settings to ensure it is not set to "Last Seven Days."
How to do this may depend on your OUtlook version which you did not mention.

--
Milly Staples [MVP - Outlook]

Post all replies to the group to keep the discussion intact.
ALWAYS post your Outlook version.
How to ask a question: http://support.microsoft.com/KB/555375


After furious head scratching, TSV asked:

| I'm very, very new to using MSOutlook. I've been receiving messages
| and now messages older than "last week" are missing? I didn't archive
| them, I didn't delete them. They are just missing, Unfortunately,
| these are very, very important messages.
|
| Where are they? How can I find them? What do I do?