包括的命名空间有：

EricDaugherty.CSES.Common
EricDaugherty.CSES.Mailbox
EricDaugherty.CSES.Net
EricDaugherty.CSES.SmtpSender
EricDaugherty.CSES.SmtpServer
其中，SmtpServer最为重要，它处理连接过来的SMTP连接，存储SMTP消息到文件、提供基于内存的消息池、维护SMTP客户端的状态。

SmtpServer命名空间包含的类有：

FileMessageSpool Stores Spooled SMTPMessages as files. 
LocalRecipientFilter Allows all email addresses addressed to the local domain specified in the constructor. 
MemoryMessageSpool Provides a memory based IMessageSpool. 
SMTPContext Maintains the current state for a SMTP client connection. 
SMTPMessage Stores an incoming SMTP Message. 
SMTPMessagePart Stores a single part of a multipart message. 
SMTPProcessor SMTPProcessor handles a single SMTP client connection. This class provides an implementation of the RFC821 specification.