Email Address Internationalization (eai) ---------------------------------------- Charter Last Modified: 2010-03-08 Current Status: Active Working Group Chair(s): Harald Alvestrand XiaoDong Lee Applications Area Director(s): Alexey Melnikov Peter Saint-Andre Applications Area Advisor: Alexey Melnikov Secretary(ies): Jiankang Yao Mailing Lists: General Discussion:ima@ietf.org To Subscribe: https://www.ietf.org/mailman/listinfo/ima Archive: http://www.ietf.org/mail-archive/web/ima Description of Working Group: Since early in the effort to internationalize domain names, which resulted in the standards associated with IDNA, it has been understood that internationalization of email address local parts is required. At the same time, email address internationalization poses a series of special problems. Constraints on the interpretation of local-parts by any system other than the final delivery one make address encoding nearly impossible. The need to use addresses in both the email envelope and in header fields, and to do so in ways that are at least compatible, suggests that this is not a simple and isolated problem. This working group will address one basic approach to email internationalization. That approach is based on the use of an SMTP extension to enable both the use of UTF-8 in envelope address local- parts and optionally in domain-parts and the use of UTF-8 in mail headers -- both in address contexts and wherever encoded-words are permitted today. Its initial target will be a set of experimental RFCs that specify the details of this approach and provide the basis for generating and testing interoperable implementations. Its work will include examining whether "downgrading" -- transforming an internationalized message to one that is compatible with unextended SMTP clients and servers and unextended MUAs -- is feasible and appropriate and, if it is, specifying a way to do so. If it is not, the WG will evaluate whether the effort is worth taking forward. Other approaches may be considered by the formation of other working groups. Key parts of this effort include extended analyses and, if necessary, proof of concept in three areas in addition to smooth operation when all systems and components along a message path have been upgraded to support the new facilities. They are o Examination of scenarios for the appearance of these facilities to users, including ways in which alternate addresses may be specified if those are needed for downgrading. o Examination of different locations at which downgrading might be required and accomplished, differentiating between requirements and capabilities at the point of origin (at or before the submission server), those that exist while the message is in transit, and those that apply after SMTP "final delivery" or in the logical vicinity or an IMAP or POP server. o Examination of the "mailing list question", i.e., how a mixture of traditional and internationalized addresses on a mailing list will impact message flows, error reports, and delivery notifications in all plausible combinations of servers and addresses, including internationalizated and traditional reverse paths. Once the Experimental RFCs are completed and implemented, the experience gathered will be evaluated. If the approach is found to have been successful (using criteria the WG will establish as an early work item), the WG will be rechartered to update the documents for processing onto the standards track. 1.6. Deliverables The following deliverables are foreseen in this charter. The WG chairs may structure the deliverables into specific documents or document sets as needed. Adding or removing documents outside of these deliverables will require a charter update. o Overview and architecture (Info) o Interworking scenarios, including the "mailing list question" (Info) o SMTP extensions specification (Exp) o Header format specification (Exp) o Downgrading specification in SMTP (Exp) o Downgrading specification in POP servers (Exp) o Downgrading specification in IMAP servers (Exp) o Results and evaluation of experiment (Info) Going forward, it is possible that the SMTP downgrading specification will go for Informational due to the difficulty of fully specifying all necessary behavior. Additional possible documents suggested: Advice for MUA implementors (Info) Goals and Milestones: Done Overview/architecture draft first Done Interworking scenarios first draft Done SMTP Extensions first draft Done Header format first draft Done Downgrading in IMAP first draft Done Downgrading in SMTP first draft Jun 2006 Interworking scenarios to IESG Done Downgrading in POP first draft Done Overview/architecture draft to IESG Done SMTP Extensions to IESG Done Header format to IESG Done Downgrading in SMTP to IESG Done Downgrading in POP to IESG Done Downgrading in IMAP to IESG Dec 2006 Results and evaluation first draft Mar 2007 Results and evaluation to IESG Mar 2007 Group recharter for standards track Internet-Drafts: Posted Revised I-D Title ------ ------- -------------------------------------------- Jun 2006 Mar 2010 Mailing Lists and Internationalized Email Addresses Request For Comments: RFC Stat Published Title ------- -- ----------- ------------------------------------ RFC4952 I Jul 2007 Overview and Framework for Internationalized Email RFC5335 E Sep 2008 Internationalized Email Headers RFC5336 E Sep 2008 SMTP Extension for Internationalized Email Addresses RFC5337 E Sep 2008 Internationalized Delivery Status and Disposition Notifications RFC5504 E Mar 2009 Downgrading Mechanism for Email Address Internationalization RFC5721 E Feb 2010 POP3 Support for UTF-8 RFC5738 E Mar 2010 IMAP Support for UTF-8 RFC5825 E Apr 2010 Displaying Downgraded Messages for Email Address Internationalization