INTERNET-DRAFT Jayantheesh S B Intended status: Standards Track Samsung Expires: May 2015 Narendra Singh Bisht Samsung November 17, 2014 The SMTP SENTCOPY Extension draft-jayantheesh-smtp-sentcopy-01 Abstract This memo defines an extension to the SMTP service whereby a server can advertise the extent of its ability to copy the emails, which are sent by an IMAP email client to IMAP Sent folders automatically. Status of this Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. This document may not be modified, and derivative works of it may not be created, except to publish it as an RFC and to translate it into languages other than English. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. 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Jayantheesh & Narendra Expires May, 2015 [Page 1] Internet-Draft SMTP SENTCOPY November 2014 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 2 1.1. Conventions and Terminology . . . . . . . . . . . . . . . 2 2. SENTCOPY Service Extension . . . . . . . . . . . . . . . . . . . 2 3. Security Considerations . . . . . . . . . . . . . . . . . . . . 3 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 3 5. References . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 5.1 Normative References . . . . . . . . . . . . . . . . . . . . . 4 5.2 Informative References . . . . . . . . . . . . . . . . . . . . 4 6. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . . 4 7. Author's Address . .. . . . . . . . . . . . . . . . . . . . . . 4 1. Introduction Some of the SMTP servers have the ability to copy the emails which are sent by the email client to the IMAP Sent mailbox automatically. But this server capability is not advertised to the email client causes, unnecessary copy of the same mail to IMAP Sent mailbox as well. Especially in mobile device environment, copying the email twice consumes unnecessary resources, like mobile data and battery power. The SMTP SENTCOPY extension provides an ability to advertise, the SMTP server capability, to the email client thus avoiding the unnecessary copy of emails to IMAP Sent mailbox. 1.1 Conventions and Terminology 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. Example lines prefaced by "C:" are sent by the client and ones prefaced by "S:" by the server. The five characters [...] means that something has been elided. 2. SENTCOPY Service Extension As of now whenever an email client sends an email, it has to send it to the SMTP server as well as upload it to the Sent mailbox of IMAP server. Some of the SMTP servers have the ability to copy the email sent by the user to IMAP Sent mailbox also, thus avoiding unnecessary network transaction. IMAP client cannot know this SMTP server capability unless it is published as part of EHLO response. SMTP server MAY have proprietary way of copying the mails or it MAY follow any standard mechanism mentioned to copy the mails to IMAP Sent folder. In both the cases, IMAP client SHOULD be notified to avoid unnecessary copy of emails. Jayantheesh & Narendra Expires May, 2015 [Page 2] Internet-Draft SMTP SENTCOPY November 2014 By this way, mail client SHALL easily identify the capabilities of the SMTP server and avoid uploading the same emails to IMAP Sent mailbox. The Command SENTCOPY extension is defined as follows: (1) The name of the SMTP service extension is Sentcopy; (2) The EHLO keyword value associated with the extension is SENTCOPY; (3) No parameter is used with the SENTCOPY EHLO keyword; When a client wishes to send email, it first issues the EHLO command to the SMTP server. If the SMTP server responds with code 250 to the EHLO command and the response includes the EHLO keyword value SENTCOPY, then the SMTP server has indicated that it has the ability to perform the copy of emails to IMAP Sent mailbox. By looking at the keyword, client can avoid doing the copy operation to IMAP Sent mailbox. Example of SENTCOPY supported SMTP EHLO response C: EHLO example.com S: 250-example.com says hello S: 250-SIZE 35882577 S: 250-8BITMIME S: 250-PIPELINING S: 250-CHUNKING S: 250-SENTCOPY S: ... Especially in the mobile device environment, copying the same email twice consumes more device resources like device battery power and mobile data. This SHALL be avoided by publishing the SMTP capability "SENTCOPY" to the email client. Irrespective of the server side implementation, email client shall easily identify and ignore the duplicate copy of emails. 3. Security Consideration This document does not add any new security considerations to SMTP. 4. IANA Considerations The IANA is requested to add SENTCOPY to the SMTP Capabilities Registry. Jayantheesh & Narendra Expires May, 2015 [Page 3] Internet-Draft SMTP SENTCOPY November 2014 5. References 5.1 Normative References The following documents contain definitions or specifications that are necessary to understand this document properly [RFC5321] J. Klensin, "Simple Mail Transfer Protocol", AT&T Laboratories, October 2008 [RFC4468] C. Newman, "Message Submission BURL Extension", Sun Microsystems, May 2006 5. 2 Informative References The following documents describe related protocols: [RFC4467] M. Crispin, "Internet Message Access Protocol (IMAP) - URLAUTH Extension", University of Washington, May 2006 [RFC3501] Crispin, "INTERNET MESSAGE ACCESS PROTOCOL - VERSION 4rev1", University of Washington, March 2003 6. Acknowledgement TBD 7. Author's Address Jayantheesh S B Samsung Telecommunications America, 685 US Highway 202/206, Bridgewater, NJ 08807. USA Email: jayantheesh.sb@gmail.com Narendra Singh Bisht Samsung Telecommunications America, 685 US Highway 202/206, Bridgewater, NJ 08807. USA Email: narendrasingh.bisht@gmail.com Jayantheesh & Narendra Expires May, 2015 [Page 4]