Try Thunderbird
I haven't used Outlook 2003, but if I am correct, you can use Mozilla Thunderbird to import the messages and then export these messages to a standard format called the "
mbox" format.
First download and install Thunderbird. Burn it to a CD, get it into a flash stick, whatever. Then, when you first launch Thunderbird, it should allow you to import your Outlook data. Then go to
C:\Documents and Settings\username\Application Data\Thunderbird\Profiles where "username" is the username of the person who has the Outlook data installed. There should be a strangely-named folder with some random gibberish and then a default in the name. Mine is called vlm4242z.default.
Each mail folder (Inbox, Sent, etc.) is stored as two files one with no extension (e.g. INBOX), which is the mail file itself (in "mbox" format), and one with an .msf extension (e.g. INBOX.msf), which is the index (Mail Summary File) to the mail file. Copy the file without the extension to a flash stick or something. These files can be HUGE. (My "All Mail" File is over 100MB and that's just a few months. Heavy mail people could easily have files in the gigs or so. This is a good time to tell your mother to go the store and get a 4 or 8 GB flash stick if you need one.)
When you get to the Mac, just import these files into Apple Mail. These are an industry-standard format, so it will read them.
To be honest, I have never done this before, but it's good to keep in mind.
My Resources - So you can verify!
http://www.mozilla.org/support/thunderbird/faq#q2.10
http://www.mozilla.org/support/thunderbird/profile
http://www.rit.edu/its/services/desktop_support/mac/applemailimportmessages.html
