Component Capabilities

CDO for Windows 2000 includes a single COM component (Cdosys.dll) that you can use to create two basic application types:

• Messaging applications can send e-mail messages using the SMTP and NNTP protocols, or optionally using local SMTP and NNTP service pickup directories. The message can be a simple text message or a message formatted according to the Multipurpose Internet Mail Extensions (MIME) specifications.
• Transport event sinks can synchronously intercept messages that arrive to a local SMTP or NNTP service and examine the message contents and envelope fields. Based upon the content, sink code can alter the message contents or block the delivery of the message.

The following scenarios illustrate the types of tasks you can write using CDO:

• Create and send messages using the SMTP and NNTP protocols
• Append disclaimers or other notices to e-mail sent through your server
• Create ASP applications with messaging capabilities
• Detect and discard unsolicited bulk mailings
• Detect and discard inappropriate newsgroup postings
• Check inbound messages for viruses
• Forward and filter messages automatically

Unlike previous CDO components such as the CDO 1.2.1 library and the CDO 1.2.1 rendering library, CDO for Windows 2000 is not MAPI-based. CDO for Windows 2000 can only send messages using the SMTP and/or NNTP protocols, or through the pickup directory of a local SMTP or NNTP service. CDO for Windows 2000 therefore cannot send messages using the Messaging API or any installed MAPI transport provider.