RFC 3030 (rfc3030) - Page 2 of 12
SMTP Service Extensions for Transmission of Large and Binary MIME Messages
Alternative Format: Original Text Document
RFC 3030 Binary ESMTP December 2000
Document Conventions
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC 2119].
Table of Contents
1. Overview ................................................... 2
2. Framework for the Large Message Extensions ................. 3
3. Framework for the Binary Service Extension ................. 5
4. Examples ................................................... 8
4.1 Simple Chunking .......................................... 8
4.2 Pipelining BINARYMIME .................................... 8
5. Security Considerations .................................... 9
6. References ................................................. 9
7. Author's Address ........................................... 10
8. Appendix A - Changes from RFC 1830 ......................... 11
9. Full Copyright Statement ................................... 12
1. Overview
The MIME extensions to the Internet message format provides for the
transmission of many kinds of data that were previously unsupported
in Internet mail. Anticipating the need to transport the new media
more efficiently, the SMTP protocol has been extended to provide
transport for new message types. RFC 1652 defines one such extension
for the transmission of unencoded 8-bit MIME messages [8BIT]. This
service extension permits the receiver SMTP to declare support for
8-bit body parts and the sender to request 8-bit transmission of a
particular message.
One expected result of the use of MIME is that the Internet mail
system will be expected to carry very large mail messages. In such
transactions, there is a performance-based desire to eliminate the
requirement that the message be scanned for "CR LF . CR LF" sequences
upon sending and receiving to detect the end of message.
Independent of the need to send large messages, Internet mail is
increasingly multimedia. There is a need to avoid the overhead of
base64 and quoted-printable encoding of binary objects sent using the
MIME message format over SMTP between hosts that support binary
message processing.
Vaudreuil Standards Track