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Table Of Contents  The TCP/IP Guide
 9  TCP/IP Application Layer Protocols, Services and Applications (OSI Layers 5, 6 and 7)
      9  TCP/IP Key Applications and Application Protocols
           9  TCP/IP File and Message Transfer Applications and Protocols (FTP, TFTP, Electronic Mail, USENET, HTTP/WWW, Gopher)
                9  TCP/IP Electronic Mail System: Concepts and Protocols (RFC 822, MIME, SMTP, POP3, IMAP)
                     9  TCP/IP Electronic Mail Delivery Protocol: The Simple Mail Transfer Protocol (SMTP)

Previous Topic/Section
SMTP Security Issues
Previous Page
Pages in Current Topic/Section
12
3
Next Page
SMTP Replies and Reply Codes
Next Topic/Section

SMTP Commands
(Page 3 of 3)

Obsolete SMTP Commands

The commands in the preceding table are the ones that are most commonly used in SMTP today. In addition to those, there are also certain commands that were originally defined in RFC 821 but have since become obsolete. These include the following:

  • SEND, SAML (“send and mail”) and SOML (“send or mail”): RFC 821 defined a distinct mechanism for delivering mail directly to a user's terminal as opposed to a mailbox, optionally in combination with conventional e-mail delivery. These were rarely implemented and obsoleted in RFC 2821.

  • TURN: Reverses the role of the SMTP sender and receiver as described in the SMTP special features topic. This had a number of implementation and security issues and was removed from the standard in RFC 2821.

Previous Topic/Section
SMTP Security Issues
Previous Page
Pages in Current Topic/Section
12
3
Next Page
SMTP Replies and Reply Codes
Next Topic/Section

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Version 3.0 - Version Date: September 20, 2005

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