Describes the Enhanced Mail System Status Codes, a set of status codes for reporting mail system errors and delivery status notifications. http://www.ietf.org/rfc/rfc1893.txt
Describes the widely implemented Post Office Protocol (POP), which allows a client to retrieve mail that a server is holding for it. http://www.ietf.org/rfc/rfc1939.txt
Defines a framework for extending the SMTP service by defining a means whereby a server can inform a client as to the service extensions it supports. http://www.ietf.org/rfc/rfc1869.txt
Describes how mail systems on the Internet are expected to route messages based on information from the domain system. http://www.ietf.org/rfc/rfc0974.txt
Describes the Local Mail Transfer Protocol (LMTP), for transporting mail into a system where a mail receiver does not manage a queue. http://www.ietf.org/rfc/rfc2033.txt
Defines a portion of the Management Information Base (MIB) for use with network management protocols, and extends the basic Network Services Monitoring MIB to allow monitoring of Message Transfer Agents (MTAs). http://www.ietf.org/rfc/rfc1566.txt