AppleInsider Jim was first to note the upcoming closure, which brings the OS X 10.7 Lion preview service to an end.
Apple first introduced Messages beta for Mac in February, bringing cross-platform messaging support for OS X and iOS. As a replacement for the previous iChat application, Messages beta was meant to bridge the gap between Apple's computers and portable devices with "Messages Everywhere," a feature that allows users to start a conversation on one machine and move seamlessly to another.
In June, Apple cut off downloads for the beta in preparation of OS X 10.8 Mountain Lion, which replaced the beta service with the dedicated Messages application.
The email points out that users must upgrade to Mountain Lion in order to keep using the service.