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CDO Versions

If you are developing an application in an environment where different versions of the Exchange client and/or Outlook client will be used, it is helpful to know the version of the Microsoft Exchange client or Outlook 97/98/2000/2002 to determine which functionality of the object library is supported with the particular client. This list provides you with the information, which is displayed at the client Help, About menu and at the Microsoft Exchange Admin program.

If you want to programmatically determine which library version is installed on your computer, please take a look at 'Digging deeper into CDO', Tips and Tricks for a sample code snippet.

Note that the current version of CDO 1.21 only ships with Microsoft Exchange 5.5/2000 Server and Microsoft Outlook 98/2000/2002. For more information please look at the Knowledge Base articles 'Where to Acquire the Collaboration Data Objects Libraries' and 'Is CDO a Redistributable Object Library?'. Both can be found at Knowledge Base Articles about CDO & Scripting and Routing.

CDO.DLL is not included in Outlook 2007 or Exchange 2007. CDO is available as a download from Microsoft, it is no longer available on the Office CD. Exchange provides a download of it at Collaboration Data Objects, version 1.2.1

 

Product Version CDO Library Comments
Exchange 4.0 1.0a All versions (including SP's) of Exchange 4.0. Initial release of CDO 1.0 (formerly known as 'OLE Messaging 1.0'). It is an out-of-process OLE server called MDISP.EXE (resp. MDISP32.EXE for the 32-bit version) which is available in both 16-bit and 32-bit builds
Exchange 5.0 1.1 All versions of Exchange 5.0, including Sp1 and SP2. Initial release of CDO 1.1 (formerly known as 'Active Messaging 1.1'). It is an in-process OLE server called OLEMSG.DLL (resp. OLEMSG32.DLL for the 32-bit version), which is available in both 16-bit and 32-bit builds. There were a few feature enhancements in Active Messaging, but the core functionality of the library remains mostly unaltered. OLEMSG32.DLL file version 5.0.1457.3

Product Version CDO Library Comments
Exchange 5.5 1.2 Initial release of CDO 1.2x. The object library consists of the in-process OLE servers called CDO.DLL. CDO.DLL file version 5.5.1960.6

Some of the added functionality over CDO 1.1 includes support for scheduling meetings and appointments. More detailed information on the feature set of CDO 1.2 can be found in the CDO.HLP.
This file is located on the Microsoft Exchange Server 5.5 CD-ROM. Note, that an updated version is included with the Microsoft Exchange Server 5.5 Service Pack 2. You can also download the most current version of CDO.HLP from CDOLive cdo.zip (1,065 Kbyte)
Exchange 5.5 SP 1 1.21 Update release of CDO 1.2x for Exchange Server 5.5. CDO.DLL file version 5.5.2232.0
Exchange 5.5 SP 2 1.21 Update release of CDO 1.2x. CDO.DLL file version 5.5.2448.0
Exchange 5.5 SP 3 1.21 Update release of CDO 1.2x. CDO.DLL file version 5.5.2650.12
Exchange 5.5 SP 4 1.21 Current release of CDO 1.2x. CDO.DLL file version 5.5.2653.12
Exchange 2000 6.0 1.21 Initial release of CDO 1.21 with Exchange 2000. CDO.DLL file version 6.0.4417.0.
Exchange 2000 6.0 CDOEX Initial release of CDO for Exchange 2000 (AKA CDO 3.0). CDOEX.DLL file version 6.0.4417.1. Only runs on top of Exchange 2000 Server
Exchange 2000 6.0 CDOEXM Initial release of CDO Management Objects for Exchange 2000. CDOEXM.DLL file version 6.0.4417.0. Runs only on top of Exchange 2000 Server or Exchange 2000 System Manager.
Exchange 2000 6.0 CDOWF Initial release of CDO Workflow Objects for Exchange 2000. CDOWF.DLL file version 6.0.4417.0. Runs only on top of Exchange 2000 Server
Exchange 2000 6.0 SP1 1.21 Updated release of CDO 1.21 with Exchange 2000. CDO.DLL file version 6.0.4712.0.
Exchange 2000 6.0 SP1 CDOEX Updated release of CDO for Exchange 2000 (AKA CDO 3.0). CDOEX.DLL file version 6.0.4712.0. Only runs on top of Exchange 2000 Server
Exchange 2000 6.0 SP1 CDOEXM Updated release of CDO Management Objects for Exchange 2000. CDOEXM.DLL file version 6.0.4712.0. Runs only on top of Exchange 2000 Server or Exchange 2000 System Manager.
Exchange 2000 6.0 SP1 CDOWF Updated release of CDO Workflow Objects for Exchange 2000. CDOWF.DLL file version 6.0.4712.0. Runs only on top of Exchange 2000 Server
Exchange 2000 6.0 SP2 1.21 Updated release of CDO 1.21 with Exchange 2000. CDO.DLL file version 6.0.5762.0.
Exchange 2000 6.0 SP2 CDOEX Updated release of CDO for Exchange 2000 (AKA CDO 3.0). CDOEX.DLL file version 6.0.5762.0. Only runs on top of Exchange 2000 Server
Exchange 2000 6.0 SP2 CDOEXM Updated release of CDO Management Objects for Exchange 2000. CDOEXM.DLL file version 6.0.5762.0. Runs only on top of Exchange 2000 Server or Exchange 2000 System Manager.
Exchange 2000 6.0 SP2 CDOWF Updated release of CDO Workflow Objects for Exchange 2000. CDOWF.DLL file version 6.0.5762.0. Runs only on top of Exchange 2000 Server
Exchange 20006.0 SP3 1.21 Updated release of CDO 1.21 with Exchange 2000. CDO.DLL file version 6.0.6249.0.
Exchange 20006.0 SP3 CDOEX Updated release of CDO for Exchange 2000 (AKA CDO 3.0). CDOEX.DLL file version 6.0.6249.0. Only runs on top of Exchange 2000 Server
Exchange 20006.0 SP3 CDOEXM Updated release of CDO Management Objects for Exchange 2000. CDOEXM.DLL file version 6.0.6249.0. Runs only on top of Exchange 2000 Server or Exchange 2000 System Manager.
Exchange 20006.0 SP3 CDOWF Updated release of CDO Workflow Objects for Exchange 2000. CDOWF.DLL file version 6.0.6249.0. Runs only on top of Exchange 2000 Server
Outlook 97 8.0 1.0a CDO 1.0 (formerly known as 'OLE Messaging 1.0')
Outlook 97 8.01 1.1 CDO 1.1 (formerly known as 'Active Messaging 1.1'). OLEMSG32.DLL file version 5.0.1457.3
Outlook 97 8.02 1.1 See above
Outlook 97 8.03 1.1 See above
Outlook 97 8.04 1.1 See above
Outlook 98 8.5 1.21 First client release of CDO 1.2x. CDO.DLL file version 5.0.2178.0
Outlook 98 with CDO E-Mail Security Update8.5 1.21 Note that using objSession.Version still returns a version string "1.21". DO NOT INSTALL THIS UPDATE ON YOUR EXCHANGE SERVER MACHINE OTHERWISE THE EXCHANGE SERVER WILL STOP RUNNING PROPERLY. CDO 1.2x. CDO.DLL file version 5.5.2652.65.

For more information please check the Slipstick Exchange & Outlook Solution Center, Outlook CDO Security Update.

Outlook 2000 9.0 1.21 Note that CDO 1.21 is not installed by default with Outlook 2000. You must add it explicit to your installation. CDO 1.2x. CDO.DLL file version 5.0.2232.0
Outlook 2000 9.0 1.21 Comes with Office/Outlook 2000 SR1. Note that CDO 1.21 is not installed by default with Outlook 2000. You must add it explicit to your installation. CDO 1.2x. CDO.DLL file version 5.0.2448.0
Outlook 2000 with CDO E-Mail Security Update 9.0 1.21 Note that using objSession.Version still returns a version string "1.21". DO NOT INSTALL THIS UPDATE ON YOUR EXCHANGE SERVER MACHINE OTHERWISE THE EXCHANGE SERVER WILL STOP RUNNING PROPERLY. CDO 1.2x. CDO.DLL file version 5.5.2652.65.

For more information please check the Slipstick Exchange & Outlook Solution Center, Outlook CDO Security Update.
Outlook 2000 9.0 1.21 Comes with Office/Outlook 2000 SP2. Note that CDO 1.21 is not installed by default with Outlook 2000. You must add it explicit to your installation. CDO 1.2x. CDO.DLL file version 5.0.2652.65
Outlook 200210.0 1.21s Note that CDO 1.21 is not installed by default with Outlook 2002. You must add it explicit to your installation. CDO 1.2x. CDO.DLL file version 5.5.2654.6
Internet Information Server 4.0 CDONTS 1.2 Initial release of CDO for Windows NT Server. CDONTS.DLL file version 5.5.1774.11
Internet Information Server 4.0 CDONTS 1.2 Update release of CDO for Windows NT Server shipped with Exchange Server 5.5 Service Pack 3. CDONTS.DLL file version 5.5.1877.30
Internet Information Server 4.0 CDONTS 1.2 Current release of CDO for Windows NT Server shipped with Exchange Server 5.5 Service Pack 4. CDONTS.DLL file version 5.5.1877.30
Windows 20005.0 CDOSYS 2.0 Initial release of CDO for Windows 2000. Includes support for SMTP and NNTP but no mailbox, MAPI or native Exchange Server support. CDOSYS.DLL file version 6.0.3939.0
Windows 2000 5.0 CDOSYS 2.0 Service Pack 1 release of CDO for Windows 2000. CDOSYS.DLL file version 6.0.3940.3
Windows 20005.0 CDOSYS 2.0 Service Pack 2 release of CDO for Windows 2000. CDOSYS.DLL file version 6.0.3940.3