Exchange 2003 SP2 was released to the Web early this morning.
It's a good idea to install this (after a backup and testing) as there are a number of fixes in this as you can see by looking at the fix list at KB article 906669. If you look at the list you will see a lot of articles that seem to apply to Exchange 2000 and not 2003. Actually, this usually means that the fix was released for Exchange 2000 before it was ported to Exchange 2003. So the article still says Exchange 2000, but applies to Exchange 2003 as well.
Also it would be a real good idea to take a look at the "Read Me" notes at http://support.microsoft.com/kb/906671. You will see that if you are looking to enable the new feature Sender ID on your server you will want to get the Windows 2003 hotfix for the SMTP service. Otherwise the server could stop responding. Unfortunately, until Windows 2003 SP2 is released you will need to call Microsoft for this fix. I know you wish it was available for download publicly... The good news is that you shouldn't get charged for the support call.
The new feature to enable or disable MAPI access per user is a neat feature if you want to limit people to only being able to access in cached mode. The downside is that doing this for every user using ADSIEdit can get old really quick. Here is a tip:
And as always, running the newest version of EXBPA after the install would be a great idea.
Update: Corrected link to http://support.microsoft.com/kb/906671
Is KB841561 fix included in E2K3 SP2 or do we still need to apply this hotfix on E2K3 clusters running on Windows 2003 SP1?
Is the fix for KB841561 http://support.microsoft.com/?kbid=841561 included in SP2 or I need to still apply it on E2K3 SP2 Clusters running on Win2K3 SP1?
Genek, The article listing the fixes says that KB841561 is included in the fixes.
906669 Issues that are fixed in Exchange Server 2003 Service Pack 2