Diferences between CDONTS, CDOSYS, CDO, CDOEX and CDOEXM?


Collaboration Data Objects for Microsoft Windows NT Server (CDONTS) was a COM component that was included with NT SP4 ( cdont.dll). It allowed creating and sending email messages from web application scripts, typically ASP pages. It required a local SMTP service installed to handle mail delivery. CDONTS was deprecated in Windows 2000 and removed completely in Windows 2003.



Is a library (cdosys.dll) provided as a part of IIS. CDOSYS replaced the older CDONTS. CDOSYS enabled applications to route smtp messages across multiple platforms.

CDOSYS had more functionality over the CDONTS library, providing support for MIME messages and it could be run on the client side.

CDOSYS can be used from windows 2000 to windows 2008.


CDO 1.2.1

Collaboration Data Objects (CDO) is a technology for building messaging or collaboration applications. It allows creation of applications with messaging functionality, or to add messaging functionality to existing applications.

CDO is an additional scripting interface to the Messaging Application Programming Interface (MAPI) model.

CDO is available through the two CDO libraries: The CDO library and the CDO rendering library. The most important one, the CDO library allows you to send and receive mail messages and to interact with folders, attachments and address books.



CDO for Exchange Server (CDOEX) provides COM classes and interfaces you can use to manage information in the exchange store. You can send messages, list inbox contents and create appointments for example. You can only use it from an Exchange Server, not from a client.

CDOEX is used in applications that send and process emails, calendar, contact information as well as access programmatically mailbox and public folders.

CDOEX is de-emphasized in Exchange 2007 and not supported in Exchange 2010. You can instead use Exchange Web Services and even run it from a local or remote computer unlike CDOEX.



CDO for Exchange Management (CDOEXM) provides COM classes and interfaces to manage the Exchange store. You need to install the Exchange Administrative Tools on the computer.

CDOEXM is used in administrative applications and scripts to control, examine or diagnose exchange servers and stores.

CDOEXM is not supported in Exchange 2007 or 2010, you can use Powershell to perform management tasks.