One of my users has a very large contacts list.  All the contacts are
assigned categories.  She wants to address a message to all the contacts in a
particular category.  There is a total of 280 + entries.  She use to just
highlight the contacts she wanted to send to, click Action - New Message to
Contact and a new message was created.  Unfortuantely, this process crashes
with more then 262 contacts.  The error she receives is "The mesaging
interface has returned an unknown error.  If the problem persist, restart
Outlook".  The list changes frequently, so creating a ditsy list is not a
good option.  Is there any other way to address a messge to all the members
of a particular category?

The email server is Exchange 2003.  She can send message with more then 262
recipients, so it doesn't seem to be a server limitation.