That's probably your ISP imposing that restriction. You can use mail merge or a third-party tool to send individual messages instead. See http://www.slipstick.com/addins/mail.htm#massmail

Signature
Sue Mosher, Outlook MVP
Outlook and Exchange solutions at http://www.slipstick.com
Author of
Microsoft Outlook Programming: Jumpstart
for Administrators, Power Users, and Developers
http://www.outlookcode.com/jumpstart.aspx
> Outlook 2002 does not allow me to send a message to more
> than 99 recipients at one time. Why ? Any way of getting
> around this problem ?