| Platform SDK: SMTP Server Events |
[This is preliminary documentation and subject to change.]
Transport events occur as a MailMsg object proceeds through the SMTP transport core. During this process, the message is submitted, categorized, and either delivered locally or relayed to another SMTP service.
The following table lists the transport events provided.
| Event | Description |
|---|---|
| OnTransportSubmission | Occurs whenever message is submitted to the transport core. This is the same event as the CDO for Windows 2000 OnArrival event. |
| OnPreCategorize | Occurs right before a message is sent to the categorizer. |
| OnPostCategorize | Occurs right after the message has been categorized. |
The following additional events are called system component events. Each of these events translates into a series of related calls to a sink acting as a system component.
| Component Event | Description |
|---|---|
| StoreDriver | The store driver sink is responsible for providing backing storage for a MailMsg object's content and transport envelope properties. The store driver also manages deletion of these files when requested, and handles local deliver of messages.
This component handles multiple calls from the service at many times as a MailMsg object passes through the service. |
| Categorizer | The categorizer sink is responsible for providing categorization information about the message to the Advanced Queue. |
| Router | The router sink (or sinks) are responsible for determining the message type and its next hop. The router is also used by the Advanced Queue to determine link state status for various destinations, etc. |
| MsgTrackLog | Occurs when message-tracking information is being gathered for the message. This event occurs frequently. |
| MaxMsgSize | Occurs when a submitted messages has content that exceeds the currently configured maximum message size. An event sink can override the default blocking of message processing. This event normally occurs once. |
| DnsResolver | Occurs whenever a domain name needs to be resolved into an IP address. This event can occur |