Post.Office 3.5.3 version 712 is the latest release of the popular mail and list server for Mac OS X. The update adds Mac OS X 10.2 (Jaguar) support and performance enhancements. Post.Office is offered on a sliding scale, depending on how many mailboxes and mailing lists are needed. A starter package is available for US$295, supporting 100 mailboxes and 10 lists.