DOCUMENT:Q87022  28-OCT-1999  [pcmail]
TITLE   :SMTP: Definition of SMTP
PRODUCT :Microsoft Mail For PC Networks
PROD/VER:MS-DOS:3.0
OPER/SYS:
KEYWORDS:

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The information in this article applies to:

 - Microsoft Mail Gateway to SMTP, version 3.0 
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SUMMARY
=======

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 query words: pcmail

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Keywords          :  
Technology        : kbMailSearch kbMailGateSearch kbZNotKeyword3 kbMailGateSMTP300
Version           : MS-DOS:3.0

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