Naturally, Outlook 2007, the newest version of Outlook, works well on Vista. (It also works great on Windows XP, which seems to surprise many people; for some reason they thought Outlook 2007 required Vista.) Outlook 2003 works well on Vista too. Both Outlook 2003 and 2007 are fully supported on Vista and if any issues come up, Microsoft will offer public hotfixes or include the fix in future Service Packs.

We're seeing a number of complaints on the Microsoft newsgroups when Outlook 2000 or 2002 is installed on Vista. The issues we know about are listed below; there may be other problems that will come out as more people try to use these versions on Vista.

Outlook 2002 runs, but email account passwords are not saved. This is because Outlook used the protected storage interfaces to store passwords and these are no longer supported in Vista. After you enter the password during the first email check, Outlook will remember it until you close down Outlook. Unless Microsoft decides to create a publicly available hotfix to address this, you won't be able to save passwords. Since Outlook 2002 is outside of mainstream support this is unlikely to happen.

Tip: when you enter the password in Outlook 2002, the Send and Receive that brought up the password dialog may fail but future send and receives will work.
Leave Outlook open 24/7 to avoid entering it frequently.

I'm also seeing complaints that Outlook 2002 won't install because it requires IE4. I personally haven't seen that error on Vista, but saw it a few times trying to install Outlook 98 on computers with IE5 and IE6 installed. I don't know if the user is mistaken about the version they have or if it's unique to specific versions of Vista, I'm testing it on Vista Business.

Outlook 2000 in Internet Mail Only (IMO) mode fails because it uses the Windows Address Book ( wab.dll ). You can switch to Corporate/Workgroup mode, which seems to work fine, except the Startup dialog comes up each time you restart Outlook (click Next and work your way through the dialog), but with more extensive use, additional issues may come to light. If you are using Outlook 2000 for email because you need the calendar, it's probably well worth your time to try the Mail and Calendar applications included with Vista. Windows Mail is more secure than Outlook 2000 and includes anti-spam filtering. The Calendar application supports many of the features found in Outlook 2007's calendar, including calendar sharing and publishing. It makes a very nice calendar program for anyone who wants a calendar but doesn't need the power of Outlook.

I haven't tested Outlook 98 yet, but like Outlook 2000, IMO mode will not work because of the missing wab.dll. Corporate mode may work ok, but I recommend using Vista's Mail and Calendar programs instead - Outlook 98 is just too insecure.

I also haven't tested Outlook 97 on Vista yet, in part because the CD is in a box I haven't unpacked yet. It's hard to fathom someone using the latest, greatest Windows OS but keeping a 10 year old email application that wasn't very good to begin with. Because of the lack of features, bugs and sluggishness, it's highly recommended you either upgrade to Outlook 2007 or use Vista's Mail and Calendar instead.

Microsoft's currently official word on support for Outlook 2000/2002 on Vista? They support it, but won't fix any problems users might encounter because those versions are in Extended Support.

From KB 932087, Description of the versions of Office that are supported on Windows Vista:

"Microsoft Office 2000, Microsoft Office XP, Microsoft Office 2003, and the 2007 Microsoft Office suites are all supported on Windows Vista. The 2007 Office suites were extensively tested on Windows Vista for best compatibility. "

And

"Because Office 2000 and Office XP are in Extended Support, there have been no fixes for issues that occur when these products are run on Windows Vista. "

"Because these versions of Office are in Extended Support, there will no more service packs for them."

Microsoft clearly has a much different definition of "supported" than many of us. Either they are "supported" on Vista and problems that arise will be fixed, or they are not supported, not guaranteed to work, and won't be fixed if there are issues.

Yes, the applications in the Office suites might work just fine, but they might not. Just don't tell us they are "supported" if you aren't going to make an effort to fix problems that will affect everyone who tries using "supported"
applications such as Outlook 2000 or 2002 on Vista.

Description of the versions of Office that are supported on Windows Vista
http://support.microsoft.com/kb/932087

Do your customers a favor and don't play word games. Be truthful, tell users Office 2000 and 2002 should work and if there are problems, you won't issue fixes because these applications are no longer supported.

Although Exchange 2007 is 64bit for production machines, there is a 32 bit version is available for testing, training, and demo scenarios on older hardware or virtual servers. It is not approved for production use.

The 32 bit version is available only as a 120 day trial and it will not be available though MSDN or volume licensing and you cannot buy the 32 bit version.
If you need to test it for periods longer than 120 days, the software will nag you but continue to run.

Both 32 and 64 bit trial versions are available as trial versions. If you install the 64 bit trial version in a production environment, you can enter your fully licensed key to "upgrade" from the trial.

Exchange Server 2007 - Evaluation Software
http://www.microsoft.com/downloads/details.aspx?FamilyID=444c259e-605f-4a82-96d5-a2f448c9d4ff&DisplayLang=en

CDO is no longer included on the disk with Outlook 2007 or Exchange 2007, it's provided as a web download. If you use an application with either product that depends on CDO, you'll need to download CDO. Operating systems supported by this download are Windows 2000, Windows Server 2003, and Windows XP.

Collaboration Data Objects, Version 1.2.1
http://www.microsoft.com/downloads/details.aspx?FamilyID=2714320d-c997-4de1-986f-24f081725d36&displaylang=en