After last week's release of Mac OS X 10.6.5, a number of users of the Server version of the operating system reported issues with the release, most notably a problem in which certain users were receiving mail intended for other parties. By the weekend, Apple had pulled both the combo and delta versions of Mac OS X 10.6.5 Server.
Yesterday, Apple released revised delta and combo versions of the update, moving from build 10H574 to 10H575. According to the security notes accompanying the "Version 1.1" release, the tweaked version does in fact address the mail issue.
A memory aliasing issue in Dovecot's handling of user names exists in Mac OS X Server v10.6.5 (10H574). On systems configured with Dovecot as a mail server, a user may receive mail that was intended for other users. This issue is addressed through improved memory management. Dovecot is only provided with Mac OS X Server systems. This issue only affects systems running Mac OS X Server v10.6.5 (10H574). This issue does not affect the Dovecot open source project.Apple notes in its general support document on the Mac OS X 10.6.5 Server release that users who previously upgraded to the initial build released last week should reapply the update using the new version.
Mac OS X Server v10.6.5 (build 10H575), released on November 15, 2010, includes security content described in this article. If you installed Mac OS X Server v10.6.5 (build 10H574), released on November 10, 2010, you should reinstall the Mac OS X Server v10.6.5 Update.
Important: If you downloaded the standalone installer of Mac OS X Server v10.6.5 (build 10H574) prior to November 15, 2010, do not install it on a system running Mac OS X Server v10.6.5 (build 10H575), as that would revert the server to build 10H574.