From How can I display the Spam Confidence Level (SCL) score in Outlook 2003? :
Microsoft Exchange Intelligent Message
Filter is a product developed by
Microsoft to help companies reduce the
amount of unsolicited commercial
e-mail (UCE), or spam, received by
users. You can read more about IMF on
the page.
When an external user sends e-mail
messages to an Exchange server with
Intelligent Message Filter enabled,
IMF evaluates the textual content of
the messages and assigns the message a
rating based on the probability that
the message is UCE or spam. All
incoming messages are marked with a
Spam Confidence Level (or SCL) rating.
SCL is a "rating system" that on a
scale from -1 (only used for
authenticated users) to 10, will tell
Outlook or OWA whether or not the
e-mail should be moved to the Junk
E-mail folder (depending on the user's
settings).
The article shows two methods for how to view the SCL rating in Outlook 2003. Use one of them to display it for your wife's email and compare this with email that's not marked as junk. Please note that only external mail is interesting, as internal mail is in theory never junked.
Once you know your wife's SCL level, and if it does seem in effect to be somewhat high, read the following two articles:
How can I configure Intelligent Message Filter in Exchange SP2?
although this is more for the administrator of the company's Exchange server.
Bug in the Intelligent Message Filter (IMF) interface
may explain the problem if the SCL level of your wife's mail is one below what the administrator thinks is his SCL junk threshold.