Add the following entry into the Win.ini file (by using either the plain text editor or the Sysedit utility), under the Mail heading. Some lines may exist, but all are needed for this feature. After you add these lines, reboot your computer:
[Mail]
MAPI=1
CMC=1
CMCDLLNAME=mapi.dll
CMCDLLNAME32=mapi32.dll
MAPIX=1
MAPIXVER=1.0.0.1
OLEMessaging=1
