Today my SBS 2008 box offered to install this optional update: “Update Rollup 3-v2 for Exchange Server 2007 Service Pack 3 (KB2530488)”. After some research, I’ve decided to decline this update.
I was curious why this rollup is in Version 2 (I hadn’t seen Version 1). That is explained in the Exchange Team Blog post: Announcing the Re-release of Exchange 2007 Service Pack 3 Update Rollup 3 (V2).
In the comments to that post, I learned about a new issue introduced by RU3. Apparently PDF attachments sent from Macs do not come through. The full discussion is in this thread, and an extensive article is available here which discusses “The problem, the fix, the problem with the fix, and the fix for the problem with the fix.” The bottom line is that while an Interim Update is available to fix the issue, you have to contact Microsoft Support to get it. I think I’ll just wait on Rollup Update 4.
I do want to commend the Microsoft developer posting as xC0000005, who wrote on March 21, “in essence it’s a bug I introduced into RU3 (sorry).” I can’t recall ever seeing a personal confession and apology about a specific bug!