I don't know if this has already been answered. I have XI and to turn it off I went to Help>Message Settings> NO > OK

I hope this helps
Frank Reid

Same problem...google searching lead me here.  Turning off Messange Settings did not solve the problem.

I went here

http://corel.custhelp.com/app/answers/detail/a_id/760540/kw/message%20center/p/155/r_id/166 and I still have a problem.

And even better....here is the actual answer when the internal option doesn't work.

Go to the Corel message folder. In XP go to Run in the
Windows Start Menu. In Vista and 7, just open the Start menu and begin
typing (which will enter text in the "Start Searching" section).
You need to type -
%appdata%
then press "Enter".
This takes you to the Windows Application Data folder for your user
account.
From there open the "Corel" folder followed by the "Messages" folder.
In that folder you will find one or more subfolders with names like
"540228824_907011". Open each one in turn and delete everything there
except
a file named "message.policy". You'll probably be just deleting a
subfolder
named "IE", but whatever you find, delete it and only leave the
"message.policy" file.