outlook isnt indexing emails properly for searching

i have a windows xp machine with outlook 2007 connected to an exchange 2007 server.

the search function (when you want to search for an email) is not working properly. I do not think my account has been indexed properly. Is there any options in outlook for this?

for e.g. when i search for a subject field in inbox of an email i received today, it does not come up but instead shows emails with the same subject line received last year....