If I am clear on this, you seem to know that a scripted solution might work:

Under Outlook 2003 you can set a rule to check when messages / meeting requests arrive and then there is an option to run a VBA script. This means that you then only need two rules.

see: http://support.microsoft.com/?kbid=306108
This wil pass the item as an object e.g. mailitem which you can access the properties e.g. subject = item.subject, body = item.body

Hold ALT and press F11 to view the VB editor, right click project > insert > module > paste the following code:

Sub CustomMailMessageRule(Item As Outlook.MailItem)
MsgBox "Mail message arrived: " & Item.Subject
MsgBox "Mail message arrived: " & Item.Body
End Sub

Sub CustomMeetingRequestRule(Item As Outlook.MeetingItem)
MsgBox "Meeting request arrived: " & Item.Subject
End Sub

Create rule > check the run script option > will now see these Subroutines select the one you want usually is mailitem.

When mail arrives will now give popup boxes (Test), problem arises when you need to create tests that require the code to open the mail such as read the body, you will get an iritating security box (if you want to rid your self of this you will need to read this:

( http://office.microsoft.com/en-gb/as...364471033.aspx )
goes into COM objects etc.

Also rule will only work client side.

Once you have confirmed that this works you can then go about customizing to your needs.

Under other versions of Outlook you would need to have a scheduled task to check new mail.

OR: Streamline your current rules, I don't kow of many organisations that really need that many rules. You can usually cut them down with a little careful planning, e.g. avoid moving mails every mail from different individuals into their own folders, user the views or categories instead.