A new Request for Comments is now available in online RFC libraries. RFC 2821 Title: Simple Mail Transfer Protocol Author(s): J. Klensin, Editor Status: Standards Track Date: April 2001 Mailbox: email@example.com Pages: 79 Characters: 192504 Updates: 1123 Obsoletes: 821, 974 I-D Tag: draft-ietf-drums-smtpupd-13.txt URL: ftp://ftp.rfc-editor.org/in-notes/rfc2821.txt This document is a self-contained specification of the basic protocol for the Internet electronic mail transport. It consolidates, updates and clarifies, but doesn't add new or change existing functionality of the following: - the original SMTP (Simple Mail Transfer Protocol) specification of RFC 821, - domain name system requirements and implications for mail transport from RFC 1035 and RFC 974, - the clarifications and applicability statements in RFC 1123, and - material drawn from the SMTP Extension mechanisms. It obsoletes RFC 821, RFC 974, and updates RFC 1123 (replaces the mail transport materials of RFC 1123). However, RFC 821 specifies some features that were not in significant use in the Internet by the mid-1990s and (in appendices) some additional transport models. Those sections are omitted here in the interest of clarity and brevity; readers needing them should refer to RFC 821. It also includes some additional material from RFC 1123 that required amplification. This material has been identified in multiple ways, mostly by tracking flaming on various lists and newsgroups and problems of unusual readings or interpretations that have appeared as the SMTP extensions have been deployed. Where this specification moves beyond consolidation and actually differs from earlier documents, it supersedes them technically as well as textually. Although SMTP was designed as a mail transport and delivery protocol, this specification also contains information that is important to its use as a 'mail submission' protocol, as recommended for POP and IMAP. Additional submission issues are discussed in RFC 2476. Section 2.3 provides definitions of terms specific to this document. Except when the historical terminology is necessary for clarity, this document uses the current 'client' and 'server' terminology to identify the sending and receiving SMTP processes, respectively. A companion document discusses message headers, message bodies and formats and structures for them, and their relationship. This document is a product of the Detailed Revision/Update of Message Standards Working Group of the IETF. This is now a Proposed Standard Protocol. 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. This announcement is sent to the IETF list and the RFC-DIST list. Requests to be added to or deleted from the IETF distribution list should be sent to IETF-REQUEST@IETF.ORG. Requests to be added to or deleted from the RFC-DIST distribution list should be sent to RFC-DIST-REQUEST@RFC-EDITOR.ORG. Details on obtaining RFCs via FTP or EMAIL may be obtained by sending an EMAIL message to rfc-info@RFC-EDITOR.ORG with the message body help: ways_to_get_rfcs. For example: To: rfc-info@RFC-EDITOR.ORG Subject: getting rfcs help: ways_to_get_rfcs Requests for special distribution should be addressed to either the author of the RFC in question, or to RFC-Manager@RFC-EDITOR.ORG. Unless specifically noted otherwise on the RFC itself, all RFCs are for unlimited distribution.echo Submissions for Requests for Comments should be sent to RFC-EDITOR@RFC-EDITOR.ORG. Please consult RFC 2223, Instructions to RFC Authors, for further information.