Microsoft is preparing to launch another volley against America Online with the release of TrueSwitch, a new service that allows AOL subscribers to move their AOL address book, AOL Mailbox, and AOL calendar over to MSN. TrueSwitch can also notify contacts of a user’s new e-mail address, forward email, and cancel a subscriber’s AOL account. TrueSwitch will work with Windows users only; Microsoft recently began testing a very limited version of MSN for Mac.