ZCS 6.0.7 is out, but for those still on the 5.x series of our server product: We are pleased to announce the release of Zimbra Collaboration Suite 5.0.24

Notable Fixes & Changes:
43387 -Redirect unsupported AJAX browsers to the HTML client upon login
37596 - Can't reply to HTML messages in Safari
41884 - renameAccount allows primary to be renamed as existing AccountAlias - breaking account
42010 - Copy Shortcuts& Right click "Copy" is not working when a mail is composed in HTML.
Bug 47586 - backup zip code needs to support zip64 format
(Further details on Zimbra Product Portal)

It's always prudent to take a backup before upgrading.

5.0.24 Network Edition: Release Notes & Downloads

5.0.24 Open Source Edition: Release Notes & Downloads

Be sure to read about the Zimbra Collaboration Suite 6.0 and subscribe to the Zimbra :: Blog for the latest news - enjoy!
-The Zimbra Team