SMTP: Definition of SMTP

Last reviewed: October 20, 1997
Article ID: Q87022
3.00 MS-DOS kb3rdparty

The information in this article applies to:

  • Microsoft Mail Gateway to SMTP, version 3.0

Simple Mail Transfer Protocol (SMTP) is designed for reliable and efficient mail transfer. It is widely used in government and education facilities and is also the standard used by the Internet for mail transfer.

The Simple Mail Transfer Protocol would be an "application layer" protocol when slotted into the OSI model. It is an open protocol because the only assumption it makes of the transport mechanism below it is that it will provide a reliable service.

In most cases, SMTP is used in conjunction with the Transmission Control Protocol (TCP) service, which provides the reliable transport layer (Service). Other transport mechanisms that are mentioned as supported in the specification are the Network Control Program (NCP) service, the Network Independent Transport Service (NITS), and the X.25 service.

Requests for comment (RFCs) provide specifications for the protocol:

  • RFC-821 specifies the exchange protocol and is the basis for SMTP.
  • RFC-822 specifies the message format.

The internet mail service is based on these RFCs.

REFERENCES

RFC 821 for SMTP

RFC-822 for the message format

For more information, query on the following words in the Microsoft Knowledge Base:

   Transmission Control Protocol/Internet Protocol


Additional reference words: 3.00 pcmail
KBCategory: kb3rdparty
KBSubcategory: MailGWSMTP


THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY.

Last reviewed: October 20, 1997
© 1998 Microsoft Corporation. All rights reserved. Terms of Use.