IdSMTPServer

TIdSMTPServer is a TIdExplicitTLSServer descendant that implements a multi-threaded SMTP (Simple Mail Transfer Protocol) server, as described in the Internet Standards documents: 

RFC 2821 - Simple Mail Transfer Protocol [SMTP]  

RFC 1869 - SMTP Service Extensions  

RFC 2554 - SMTP Service Extension for Authentication  

RFC 3207 - SMTP Service Extension for Secure SMTP over Transport Layer Security  

TIdSMTPServer allows control over basic server options and configuration using properties like AllowEHLO, NoDecode, ReceiveMode, and Messages. TIdSMTPServer also exposes event handlers used for receiving incoming mail data like OnReceiveRaw, OnReceiveMessage, and OnReceiveMessageParsed. 

TIdSMTPServer allows control over operational features of the server implementation using the command handler architecture and optional event handlers, including: 

TIdExplicitTLSServer TIdSMTP IndySupport