📄 rfc1830.txt
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RFC 1830 Binary and Large Message Transport August 1995 <LF>. Any transformation of text into non-canonical MIME to observe local storage conventions must be reversed before sending as BINARYMIME. The usual line-oriented shortcuts will break if used with BINARYMIME. The syntax of the extended MAIL command is identical to the MAIL command in [RFC821], except that a BODY parameter must appear after the address. The complete syntax of this extended command is defined in [ESMTP]. The ESMTP-keyword is BODY and the syntax for ESMTP-value is given by the syntax for body-value in [ESMTP]. If a receiver SMTP does not support the BINARYMIME message format (either by not responding with code 250 to the EHLO command, or by rejecting the BINARYMIME parameter to the MAIL FROM command, then the client SMTP must not, under any circumstances, send binary data using the DATA or BDAT commands. If the receiver-SMTP does not support BINARYMIME and the message content is a MIME object with a binary encoding, a client SMTP has two options in this case: first, it may implement a gateway transformation to convert the message into valid 7bit encoded MIME, or second, it may treat this as a permanent error and handle it in the usual manner for delivery failures. The specifics of the transformation from Binary MIME to 7bit MIME are not described by this RFC; the conversion is nevertheless constrained in the following ways: o The conversion must cause no loss of information; MIME transport encodings must be employed as needed to insure this is the case. o The resulting message must be valid 7bit MIME. As of present there are no mechanisms for converting a binary MIME object into a 8 bit-MIME object. Such a transformation will require the specification of a new MIME content-transfer-encoding, the standardization of which is discouraged by [MIME].Vaudreuil Experimental [Page 5]RFC 1830 Binary and Large Message Transport August 19955. Examples5.1 Simple Chunking The following simple dialogue illustrates the use of the large message extension to send a short psudo-RFC822 message to one recipient using the CHUNKING extension: R: <wait for connection on TCP port 25> S: <open connection to server> R: 220 cnri.reston.va.us SMTP service ready S: EHLO ymir.claremont.edu R: 250-cnri.reston.va.us says hello R: 250 CHUNKING S: MAIL FROM:<Sam@Random.com> R: 250 <Sam@Random.com>... Sender ok S: RCPT TO:<Susan@Random.com> R: 250 <Susan@random.com>... Recipient ok S: BDAT 69 LAST S: To: Susan@random.com<CR><LF> S: From: Sam@random.com<CR><LF> S: Subject: This is a bodyless test message<CR><LF> R: 250 Message OK, 69 octets received S: QUIT R: 221 Goodbye5.2 Pipelining Binarymime The following dialogue illustrates the use of the large message extension to send a BINARYMIME object to two recipients using the CHUNKING and PIPELINING extensions: R: <wait for connection on TCP port 25> S: <open connection to server> R: 220 cnri.reston.va.us SMTP service ready S: EHLO ymir.claremont.edu R: 250-cnri.reston.va.us says hello R: 250-PIPELINING R: 250-BINARYMIME R: 250 CHUNKING S: MAIL FROM:<ned@ymir.claremont.edu> BODY=BINARYMIME S: RCPT TO:<gvaudre@cnri.reston.va.us> S: RCPT TO:<jstewart@cnri.reston.va.us> R: 250 <ned@ymir.claremont.edu>... Sender and BINARYMIME ok R: 250 <gvaudre@cnri.reston.va.us>... Recipient ok R: 250 <jstewart@cnri.reston.va.us>... Recipient ok S: BDAT 100000Vaudreuil Experimental [Page 6]RFC 1830 Binary and Large Message Transport August 1995 S: (First 10000 octets of canonical MIME message data) S: BDAT 324 LAST S: (Remaining 324 octets of canonical MIME message data) R: 250 100000 bytes received R: 250 Message OK, 100324 octets received S: QUIT R: 221 Goodbye6. 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 [RFC821], or otherwise made possible by [MIME].7. Acknowledgments This document is the result of numerous discussions in the IETF SMTP Extensions Working Group and in particular due to the continued advocacy of "chunking" by Neil Katin.8. References [RFC821] Postel, J., "Simple Mail Transfer Protocol", STD 10, RFC 821, USC/Information Sciences Institute, August 1982. [RFC822] Crocker, D., "Standard for the Format of ARPA Internet Text Messages", STD 11, RFC 822, UDEL, August 1982. [MIME] Borenstein, N., and N. Freed, "Multipurpose Internet Mail Extensions", RFC 1521, Bellcore, Innosoft, June 1992. [ESMTP] Klensin, J., WG Chair, Freed, N., Editor, Rose, M., Stefferud, E., and D. Crocker, "SMTP Service Extensions" RFC 1425, United Nations University, Innosoft International, Inc., Dover Beach Consulting, Inc., Network Management Associates, Inc., The Branch Office, February 1993. [8BIT] Klensin, J., WG Chair, Freed, N., Editor, Rose, M., Stefferud, E., and D. Crocker, "SMTP Service Extension for 8bit-MIMEtransport" RFC 1426, United Nations University, Innosoft International, Inc., Dover Beach Consulting, Inc., Network Management Associates, Inc., The Branch Office, February 1993. [PIPE] Freed, N., "SMTP Service Extensions for Command Pipelining", Innosoft International, Work in Progress.Vaudreuil Experimental [Page 7]RFC 1830 Binary and Large Message Transport August 19959. Author's Address Gregory M. Vaudreuil Octel Network Services 17060 Dallas Parkway Suite 214 Dallas, TX 75248-1905 Voice/Fax: 214-733-2722 EMail: Greg.Vaudreuil@Octel.comVaudreuil Experimental [Page 8]
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