哪儿有Pop3协议和smtp协议的完整文档

[fly]

有哪位英雄知道哪儿有POP3和SMTP协议的标准,或者给我发一份,十分感谢!

[radish]

http://www.cis.ohio-state.edu/htbin/rfc/INDEX.rfc.html

[tonyhan]

look rfc1734(pop3) and rfc1425(smtp)

[dedien]

以下为POP3与SMTP的详细文档：

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POP3 AUTHentication command

Status of this Memo
This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards" (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited.


1. Introduction
This document describes the optional AUTH command, for indicating an authentication mechanism to the server, performing an authentication protocol exchange, and optionally negotiating a protection mechanism for subsequent protocol interactions. The authentication and protection mechanisms used by the POP3 AUTH command are those used by IMAP4.


2. The AUTH command
AUTH mechanism

Arguments:
a string identifying an IMAP4 authentication mechanism, such as defined by [IMAP4-AUTH]. Any use of the string "imap" used in a server authentication identity in the definition of an authentication mechanism is replaced with the string "pop".

Restrictions:
may only be given in the AUTHORIZATION state

Discussion:
The AUTH command indicates an authentication mechanism to the server. If the server supports the requested authentication mechanism, it performs an authentication protocol exchange to authenticate and identify the user. Optionally, it also negotiates a protection mechanism for subsequent protocol interactions. If the requested authentication mechanism is not supported, the server



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should reject the AUTH command by sending a negative response.

The authentication protocol exchange consists of a series of server challenges and client answers that are specific to the authentication mechanism. A server challenge, otherwise known as a ready response, is a line consisting of a "+" character followed by a single space and a BASE64 encoded string. The client answer consists of a line containing a BASE64 encoded string. If the client wishes to cancel an authentication exchange, it should issue a line with a single "*". If the server receives such an answer, it must reject the AUTH command by sending a negative response.

A protection mechanism provides integrity and privacy protection to the protocol session. If a protection mechanism is negotiated, it is applied to all subsequent data sent over the connection. The protection mechanism takes effect immediately following the CRLF that concludes the authentication exchange for the client, and the CRLF of the positive response for the server. Once the protection mechanism is in effect, the stream of command and response octets is processed into buffers of ciphertext. Each buffer is transferred over the connection as a stream of octets prepended with a four octet field in network byte order that represents the length of the following data. The maximum ciphertext buffer length is defined by the protection mechanism.

The server is not required to support any particular authentication mechanism, nor are authentication mechanisms required to support any protection mechanisms. If an AUTH command fails with a negative response, the session remains in the AUTHORIZATION state and client may try another authentication mechanism by issuing another AUTH command, or may attempt to authenticate by using the USER/PASS or APOP commands. In other words, the client may request authentication types in decreasing order of preference, with the USER/PASS or APOP command as a last resort.

Should the client successfully complete the authentication exchange, the POP3 server issues a positive response and the POP3 session enters the TRANSACTION state.

Possible Responses:

+OK maildrop locked and ready
-ERR authentication exchange failed



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Examples:

S: +OK POP3 server ready
C: AUTH KERBEROS_V4
S: + AmFYig==
C: BAcAQU5EUkVXLkNNVS5FRFUAOCAsho84kLN3/IJmrMG+25a4DT
+nZImJjnTNHJUtxAA+o0KPKfHEcAFs9a3CL5Oebe/ydHJUwYFd
WwuQ1MWiy6IesKvjL5rL9WjXUb9MwT9bpObYLGOKi1Qh
S: + or//EoAADZI=
C: DiAF5A4gA+oOIALuBkAAmw==
S: +OK Kerberos V4 authentication successful
...
C: AUTH FOOBAR
S: -ERR Unrecognized authentication type

Note: the line breaks in the first client answer are for editorial clarity and are not in real authentica- tors.



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3. Formal Syntax
The following syntax specification uses the augmented Backus-Naur Form (BNF) notation as specified in RFC 822.

Except as noted otherwise, all alphabetic characters are case- insensitive. The use of upper or lower case characters to define token strings is for editorial clarity only. Implementations MUST accept these strings in a case-insensitive fashion.


ATOM_CHAR ::= <any CHAR except atom_specials>

atom_specials ::= "(" / ")" / "{" / SPACE / CTLs / "%" / "*" /
<"> / "\"

auth ::= "AUTH" 1*(SPACE / TAB) auth_type *(CRLF base64)
CRLF

auth_type ::= 1*ATOM_CHAR

base64 ::= *(4base64_CHAR) [base64_terminal]

base64_char ::= "A" / "B" / "C" / "D" / "E" / "F" / "G" / "H" /
"I" / "J" / "K" / "L" / "M" / "N" / "O" / "P" /
"Q" / "R" / "S" / "T" / "U" / "V" / "W" / "X" /
"Y" / "Z" /
"a" / "b" / "c" / "d" / "e" / "f" / "g" / "h" /
"i" / "j" / "k" / "l" / "m" / "n" / "o" / "p" /
"q" / "r" / "s" / "t" / "u" / "v" / "w" / "x" /
"y" / "z" /
"0" / "1" / "2" / "3" / "4" / "5" / "6" / "7" /
"8" / "9" / "+" / "/"
;; Case-sensitive

base64_terminal ::= (2base64_char "==") / (3base64_char "=")

CHAR ::= <any 7-bit US-ASCII character except NUL,
0x01 - 0x7f>

continue_req ::= "+" SPACE base64 CRLF

CR ::= <ASCII CR, carriage return, 0x0C>

CRLF ::= CR LF

CTL ::= <any ASCII control character and DEL,
0x00 - 0x1f, 0x7f>



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LF ::= <ASCII LF, line feed, 0x0A>

SPACE ::= <ASCII SP, space, 0x20>

TAB ::= <ASCII HT, tab, 0x09>


4. References
[IMAP4-AUTH] Myers, J., "IMAP4 Authentication Mechanisms", RFC 1731, Carnegie Mellon, December 1994.


5. Security Considerations
Security issues are discussed throughout this memo.


6. Author's Address
John G. Myers
Carnegie-Mellon University
5000 Forbes Ave
Pittsburgh, PA 15213

EMail: [e-mail]

------------------------------------------------------------------------

SMTP Service Extensions

Status of this Memo
This RFC specifies an IAB standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "IAB Official Protocol Standards" for the standardization state and status of this protocol. Distribution of this memo is unlimited.


1. Abstract
This memo defines a framework for extending the SMTP service by defining a means whereby a server SMTP can inform a client SMTP as to the service extensions it supports. Standard extensions to the SMTP service are registered with the Internet Assigned Numbers Authority (IANA). This framework does not require modification of existing SMTP clients or servers unless the features of the service extensions are to be requested or provided.


2. Introduction
The Simple Mail Transfer Protocol (SMTP) [1] has provided a stable, effective basis for the relay function of message transfer agents. Although a decade old, SMTP has proven remarkably resilient. Nevertheless, the need for a number of protocol extensions has become evident. Rather than describing these extensions as separate and haphazard entities, this document enhances SMTP in a straightforward fashion that provides a framework in which all future extensions can be built in a single consistent way.


3. Framework for SMTP Extensions
For the purpose of service extensions to SMTP, SMTP relays a mail object containing an envelope and a content.



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(1) The SMTP envelope is straightforward, and is sent as a series of SMTP protocol units: it consists of an originator address (to which error reports should be directed); a delivery mode (e.g., deliver to recipient mailboxes); and, one or more recipient addresses.

(2) The SMTP content is sent in the SMTP DATA protocol unit and has two parts: the headers and the body. The headers form a collection of field/value pairs structured according to RFC 822 [2], whilst the body, if structured, is defined according to MIME [3]. The content is textual in nature, expressed using the US ASCII repertoire (ANSI X3.4-1986). Although extensions (such as MIME) may relax this restriction for the content body, the content headers are always encoded using the US ASCII repertoire. The algorithm defined in [4] is used to represent header values outside the US ASCII repertoire, whilst still encoding them using the US ASCII repertoire.

Although SMTP is widely and robustly deployed, some parts of the Internet community might wish to extend the SMTP service. This memo defines a means whereby both an extended SMTP client and server may recognize each other as such and the server can inform the client as to the service extensions that it supports.

It must be emphasized that any extension to the SMTP service should not be considered lightly. SMTP's strength comes primarily from its simplicity. Experience with many protocols has shown that:

protocols with few options tend towards ubiquity, whilst protocols with many options tend towards obscurity.

This means that each and every extension, regardless of its benefits, must be carefully scrutinized with respect to its implementation, deployment, and interoperability costs. In many cases, the cost of extending the SMTP service will likely outweigh the benefit.

Given this environment, the framework for the extensions described in this memo consists of:

(1) a new SMTP command (section 4)

(2) a registry of SMTP service extensions (section 5)

(3) additional parameters to the SMTP MAIL FROM and RCPT TO commands (section 6).



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4. The EHLO command
A client SMTP supporting SMTP service extensions should start an SMTP session by issuing the EHLO command instead of the HELO command. If the SMTP server supports the SMTP service extensions it will give a successful response (see section 4.1), a failure response (see 4.2), or an error response (4.3). If the SMTP server does not support any SMTP service extensions it will generate an error response (see section 4.4).

The syntax for this command, using the ABNF notation of [2], is:


ehlo-cmd ::= "EHLO" SP domain CR LF

If successful, the server SMTP responds with code 250. On failure, the server SMTP responds with code 550. On error, the server SMTP responds with one of codes 500, 501, 502, 504, or 421.

This command is issued instead of the HELO command, and may be issued at any time that a HELO command would be appropriate. That is, if the EHLO command is issued, and a successful response is returned, then a subsequent HELO or EHLO command will result in the server SMTP replying with code 503. A client SMTP must not cache any information returned if the EHLO command succeeds. That is, a client SMTP must issue the EHLO command at the start of each SMTP session if information about extended facilities is needed.


4.1. Successful response
If the server SMTP implements and is able to perform the EHLO command, it will return code 250. This indicates that both the server and client SMTP are in the initial state, that is, there is no transaction in progress and all state tables and buffers are cleared.

Normally, this response will be a multiline reply. Each line of the response contains a keyword and, optionally, one or more parameters. The syntax for a positive response, using the ABNF notation of [2], is:



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ehlo-ok-rsp ::= "250" domain [ SP greeting ] CR LF
/ ( "250-" domain [ SP greeting ] CR LF
*( "250-" ehlo-line CR LF )
"250" SP ehlo-line CR LF )

; the usual HELO chit-chat
greeting ::= 1*<any character other than CR or LF>

ehlo-line ::= ehlo-keyword *( SP ehlo-param )

ehlo-keyword ::= (ALPHA / DIGIT) *(ALPHA / DIGIT / "-")

; syntax and values depend on ehlo-keyword
ehlo-param ::= 1*<any CHAR excluding SP and all
control characters (US ASCII 0-31
inclusive)>

ALPHA ::= <any one of the 52 alphabetic characters
(A through Z in upper case, and,
a through z in lower case)>

DIGIT ::= <any one of the 10 numeric characters
(0 through 9)>

CR ::= <the carriage-return character
(ASCII decimal code 13)>
LF ::= <the line-feed character
(ASCII decimal code 10)>
SP ::= <the space character
(ASCII decimal code 32)>

Although EHLO keywords may be specified in upper, lower, or mixed case, they must always be recognized and processed in a case- insensitive manner. This is simply an extension of practices begun in RFC 821.

The IANA maintains a registry of standard SMTP service extensions. Associated with each such extension is a corresponding EHLO keyword value. Each service extension registered with the IANA is defined by a standards-track RFC, and such a definition includes:

(1) the textual name of the SMTP service extension;

(2) the EHLO keyword value associated with the extension;

(3) the syntax and possible values of parameters associated with the EHLO keyword value;



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(4) any additional SMTP verbs associated with the extension (additional verbs will usually be, but are not required to be, the same as the EHLO keyword value);

(5) any new parameters the extension associates with the MAIL FROM or RCPT TO verbs; and,

(6) how support for the extension affects the behavior of a server and client SMTP.

In addition, any EHLO keyword value that starts with an upper or lower case "X" refers to a local SMTP service extension, which is used through bilateral, rather than standardized, agreement. Keywords beginning with "X" may not be used in a registered service extension.

Any keyword values presented in the EHLO response that do not begin with "X" must correspond to an SMTP service extension registered with IANA. A conforming server must not offer non "X" prefixed keyword values that are not described in a registered extension.

Additional verbs are bound by the same rules as EHLO keywords; specifically, verbs begining with "X" are local extensions that may not be standardized and verbs not beginning with "X" must always be registered.


4.2. Failure response
If for some reason the server SMTP is unable to list the service extensions it supports, it will return code 554.

In the case of a failure response, the client SMTP should issue either the HELO or QUIT command.


4.3. Error responses from extended servers
If the server SMTP recognizes the EHLO command, but the command argument is unacceptable, it will return code 501.

If the server SMTP recognizes, but does not implement, the EHLO command, it will return code 502.

If the server SMTP determines that the SMTP service is no longer available (e.g., due to imminent system shutdown), it will return code 421.

In the case of any error response, the client SMTP should issue either the HELO or QUIT command.



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4.4. Responses from servers without extensions
A server SMTP that conforms to RFC 821 but does not support the extensions specified here will not recognize the EHLO command and will consequently return code 500, as specified in RFC 821.


5. Initial IANA Registry
The IANA's initial registry of SMTP service extensions consists of these entries:


Service Ext EHLO Keyword Parameters Verb Added Behavior
------------- ------------ ---------- ---------- ------------------
Send SEND none SEND defined in RFC 821
Send or Mail SOML none SOML defined in RFC 821
Send and Mail SAML none SAML defined in RFC 821
Expand EXPN none EXPN defined in RFC 821
Help HELP none HELP defined in RFC 821
Turn TURN none TURN defined in RFC 821

which correspond to those SMTP commands which are defined as optional in [5]. (The mandatory SMTP commands, according to [5], are HELO, MAIL, RCPT, DATA, RSET, VRFY, NOOP, and QUIT.)


6. MAIL FROM and RCPT TO Parameters
It is recognized that several of the extensions planned for SMTP will make use of additional parameters associated with the MAIL FROM and RCPT TO command. The syntax for these commands, again using the ABNF notation of [2] as well as underlying definitions from [1], is:


esmtp-cmd ::= inner-esmtp-cmd [SP esmtp-parameters] CR LF
esmtp-parameters ::= esmtp-parameter *(SP esmtp-parameter)
esmtp-parameter ::= esmtp-keyword ["=" esmtp-value]
esmtp-keyword ::= (ALPHA / DIGIT) *(ALPHA / DIGIT / "-")

; syntax and values depend on esmtp-keyword
esmtp-value ::= 1*<any CHAR excluding "=", SP, and all
control characters (US ASCII 0-31
inclusive)>

; The following commands are extended to
; accept extended parameters.
inner-esmtp-cmd ::= ("MAIL FROM:<" reverse-path ">") /
("RCPT TO:<" forward-path ">")

All esmtp-keyword values must be registered as part of the IANA registration process described above. This definition only provides



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the framework for future extension; no extended MAIL FROM or RCPT TO parameters are defined by this RFC.


6.1. Error responses
If the server SMTP does not recognize or cannot implement one or more of the parameters associated with a particular MAIL FROM or RCPT TO command, it will return code 555.

If for some reason the server is temporarily unable to accomodate one or more of the parameters associated with a MAIL FROM or RCPT TO command, and if the definition of the specific parameter does not mandate the use of another code, it should return code 455.

Errors specific to particular parameters and their values will be specified in the parameter's defining RFC.


7. Received: Header Field Annotation
SMTP servers are required to add an appropriate Received: field to the headers of all messages they receive. A "with ESMTP" clause should be added to this field when any SMTP service extensions are used. "ESMTP" is hereby added to the list of standard protocol names registered with IANA.


8. Usage Examples
(1) An interaction of the form:


S: <wait for connection on TCP port 25>
C: <open connection to server>
S: 220 dbc.mtview.ca.us SMTP service ready
C: EHLO ymir.claremont.edu
S: 250 dbc.mtview.ca.us says hello
...

indicates that the server SMTP implements only those SMTP commands which are defined as mandatory in [5].

(2) In contrast, an interaction of the form:


S: <wait for connection on TCP port 25>
C: <open connection to server>
S: 220 dbc.mtview.ca.us SMTP service ready
C: EHLO ymir.claremont.edu
S: 250-dbc.mtview.ca.us says hello
S: 250-EXPN
S: 250-HELP



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S: 250-8BITMIME
S: 250-XONE
S: 250 XVRB
...

indicates that the server SMTP also implements the SMTP EXPN and HELP commands, one standard service extension (8BITMIME), and two non-standard service extensions (XONE and XVRB).

(3) Finally, a server that does not support SMTP service extensions would act as follows:


S: <wait for connection on TCP port 25>
C: <open connection to server>
S: 220 dbc.mtview.ca.us SMTP service ready
C: EHLO ymir.claremont.edu
S: 500 Command not recognized: EHLO
...

The 500 response indicates that the server SMTP does not implement the extensions specified here. The client would normally send RSET to reset the connection, and, after getting a successful reply, send a HELO command and proceed as specified in RFC 821.


9. Security Considerations
This RFC does not discuss security issues and is not believed to raise any security issues not already endemic in electronic mail and present in fully conforming implementations of RFC-821. It does provide an announcement of server mail capabilities via the response to the EHLO verb. However, all information provided by announcement of any of the initial set of service extensions defined by this RFC can be readily deduced by selective probing of the verbs required to transport and deliver mail. The security implications of service extensions described in other RFCs should be dealt with in those RFCs.


10. Acknowledgements
This document represents a synthesis of the ideas of many people and reactions to the ideas and proposals of others. Randall Atkinson, Craig Everhart, Risto Kankkunen, and Greg Vaudreuil contributed ideas and text sufficient to be considered co-authors. Other important suggestions, text, or encouragement came from Harald Alvestrand, Jim Conklin, Mark Crispin, Frank da Cruz, 'Olafur Gudmundsson, Per Hedeland, Christian Huitma, Neil Katin, Eliot Lear, Harold A.



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Miller, Dan Oscarsson, Julian Onions, Rayan Zachariassen, and the contributions of the entire IETF SMTP Working Group. Of course, none of the individuals are necessarily responsible for the combination of ideas represented here. Indeed, in some cases, the response to a particular criticism was to accept the problem identification but to include an entirely different solution from the one originally proposed.


11. References
[1] Postel, J., "Simple Mail Transfer Protocol", STD 10, RFC 821, USC/Information Sciences Institute, August 1982.

[2] Crocker, D., "Standard for the Format of ARPA Internet Text Messages", STD 11, RFC 822, UDEL, August 1982.

[3] Borenstein, N., and N. Freed, "Multipurpose Internet Mail Extensions", RFC 1341, Bellcore, Innosoft, June 1992.

[4] Moore, K., "Representation of Non-ASCII Text in Internet Message Headers", RFC 1342, University of Tennessee, June 1992.

[5] Braden, R., "Requirements for Internet Hosts - Application and Support", STD 3, RFC 1123, USC/Information Sciences Institute, October 1989.


12. Chair, Editor, and Authors' Addresses
John Klensin, WG Chair
United Nations University
PO Box 500, Charles Street Station
Boston, MA 02114-0500 USA

Phone: [phone]
Fax: [phone]
Email: [e-mail]

Ned Freed, Editor
Innosoft International, Inc.
250 West First Street, Suite 240
Claremont, CA 91711 USA

Phone: [phone]
Fax: [phone]
Email: [e-mail]



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Marshall T. Rose
Dover Beach Consulting, Inc.
420 Whisman Court
Moutain View, CA 94043-2186 USA

Phone: [phone]
Fax: [phone]
Email: [e-mail]

Einar A. Stefferud
Network Management Associates, Inc.
17301 Drey Lane
Huntington Beach, CA, 92647-5615 USA

Phone: [phone]
Fax: [phone]
Email: [e-mail]

David H. Crocker
The Branch Office
USA

Email: [e-mail]

[PerduBug]

[e-mail]

[TeamD]

我在里有，但是是E 文的。我可E-mail 一个给你。

[ninesun]

访问这个链接http://www.csl.sony.co.jp/cgi-bin/hyperrfc?rfc-index.txt