The Exchange Team released Rollup 12 for Exchange Server 2010 Service Pack 3 (KB3096066) as well as Rollup 18 for Exchange Server 2007 Service Pack 3 (KB3078672). These update raise version numbers to 14.3.279.2 and 8.3.445.0 respectively.

Apart from a Daylight Savings Time update, documented here, these Rollups contain the following fixes:

Exchange 2010 SP3 Rollup 12:

• KB 3048372 Exchange Calendar items are shifted incorrectly when some Windows DST updates are applied
• KB 3096125 CryptographicException error when Edge Transport service crashes in an Exchange Server 2010 environment
• KB 3097219 Organizer’s name isn’t displayed in the subject of the recurring meeting requests in Exchange Server 2010
• KB 3106421 Very long URLs in an email message don’t open in OWA in Internet Explorer
• KB 3115809 Mailboxes can be accessed when the DefaultNetworkCredentials option is selected when you use Exchange Web Services Managed API to connect to Exchange Server

Exchange Server 2007 SP3 Rollup 18:

• KB 3106421 Very long URLs in an email message don’t open in OWA in Internet Explorer

Notes:

• If you want to speed up the update process for systems without internet access, follow the procedure described here to disable publisher’s certificate revocation checking.
• If you got an Exchange 2010 DAG, and want to properly update the DAG members, check the instructions here.
• As for any Hotfix, Rollup, Service Pack or Cumulative Update, apply this update to a acceptance environment first, prior to implementing it in production. When you lack such facilities, hold out a certain period and monitor the comments on the release article or TechNet forum for any issues.

Rollups are cumulative per service pack level, i.e. they contain fixes released in earlier update Rollups for the same product level (RTM, SP). This means you can apply the latest Rollup after installing a fresh installation of RTM or SPx version, for that product level.

You can download Exchange 2010 SP3 Rollup 12 here and Exchange 2007 SP3 Rollup 18 here.