What's new in the Email WorldIMAP/LEMONADE/SIEVE

(no DKIM or EAI)

Alexey Melnikov<alexey.melnikov@isode.com>

IMAPEXT WG

IMAP is message access protocol, designed to make clients easier

Tasked to produce extensions to IMAP (RFC 3501), such as:

● Sorting, threading, and viewing● Access Control Lists● Message-level annotations● I18N

IMAP building blocks to build cool toys

LEMONADE WG

●Lemonade is tasked to provide a set of enhancements and profiles of Internet email submission, transport, and retrieval protocols to facilitate operation on platforms with constrained resources, or communications links with high latency or limited bandwidth.●Lemonade Profile recently published (RFC 4550)

Forward-without-download Push Email (IMAP IDLE) Quick Flag Changes Resynchronization

(CONDSTORE) Reduction of bandwith/round-trips

[Soon to be] completed work in IMAPEXT WG

● April 2006 - Collected Extensions to IMAP4 ABNF (RFC 4466)● October 2006 - Comparators (Internet Application Protocol

Collation Registry) - draft-newman-i18n-comparator-14.txt - in RFC editor queue

● October 2006 - IMAP4 LIST Command Extensions (draft-ietf-imapext-list-extensions-18.txt) - in RFC editor queue, waiting for IMAP I18N document to finish

● IMAP ANNOTATE Extension (draft-ietf-imapext-annotate-16.txt) - in IESG evaluation

● IMAP METADATA Extension (draft-daboo-imap-annotatemore-10.txt) – per mailbox annotations

● The IMAP ENABLE Extension (draft-gulbrandsen-imap-enable-00.txt)

Recently completed work in IMAPEXT/LEMONADE WGs

● Dec 2005 - IMAP4 ACL Extension (RFC 4314)

● Dec 2005 - Update to UIDPLUS (RFC 2359), RFC 4315● Jun 2006 - IMAP Extension for Conditional STORE Operation

or Quick Flag Changes Resynchronization (RFC 4551)

● Apr 2006 - IMAP CATENATE Extension (RFC 4469)● May 2006 - Message Submission BURL Extension (RFC 4468)● May 2006 - IMAP - URLAUTH Extension (RFC 4467)

Forward-without-download

Lemonade interop eventOctober 2006, London

● 4 servers● 2 clients (more promised soon)● Bugs found, but things mostly work

IMAP URL● Some [mostly minor] issues are found in F-W-D,

CONDSTORE documents

Relative-path IMAP URLs● draft-ietf-lemonade-rfc2192bis-02.txt

Needs review by URI experts● Relative-paths are only used in IMAP CATENATE so

far● IMAP mailbox hierarchy separator can be different in

different server: INBOX.Apple.Green INBOX/Apple/Green

● What is the meaning of: ..;UIDVALIDITY=385759045/;UID=20 .;UIDVALIDITY=385759045/;UID=20/..

Future work● IMAPEXT

I18N document SORT/THREAD

● LEMONADE IMAP/SMTP compression Quick reconnect Content conversion Improvements to SEARCH command Filtered views Controlling in-band/out-band notifications Multimedia streaming

IMAP Internationalization

● draft-ietf-imapext-i18n-07.txt [expired]● draft-ietf-eai-imap-utf8-00.txt● Issues

Internationalized error responses● Something similar is needed in SMTP

Usernames/passwords● Frequently used as email addresses

Mailbox names Domains, Addresses and Mail Headers

● EAI WG IMAP keywords (?) ...

IMAP/SMTP compression

● Works in the same way as TLS or SASL security layer

● Stop gap until TLS compression is deployed in OSes

● IMAP document is past WGLC● SMTP needs to be written

Would there be enough saving to make it worthwhile

Quick reconnect

● Goal: minimize reconnection cost when connectivity is poor

● IMAP: was a server side mechanism at first● SMTP: revise RFC 1845 (SMTP Service

Extension for Checkpoint/Restart) (?) This might be less of an issue when BURL (F-W-D)

is deployed

Content conversion● Content conversion (draft-ietf-lemonade-convert-05)

E.g. convert a Word attachment to PDF Similar to recently done IMAP BINARY extension In WGLC now

Various improvements to SEARCH

● Improvements to SEARCH command Aug 2006 - IMAP4 extension to SEARCH command

for controlling what kind of information is returned (draft-melnikov-imap-search-ret-03.txt) - in RFC editor queue

Virtual Mailboxes / Persistent searches (next slide) draft-melnikov-imap-search-res-03.txt draft-melnikov-imapext-filters-00.txt draft-melnikov-imapext-multimailbox-search-01.txt draft-ietf-lemonade-search-within-02.txt

Filtered Views● Two proposals:● draft-cridland-imap-context-00.txt

Persistent searches + paged results● draft-ietf-lemonade-vfolder-01.txt

Virtual Mailboxes

Controlling in-band notifications for mailstore events

● Push email (IMAP IDLE, RFC 2177) works great(*) and is widely deployed

● However servers report different events● Need a catalog of events

draft-ietf-lemonade-msgevent-00.txt● Need a way for the client to request specific

events draft-gulbrandsen-imap-notify-01.txt

Other bandwidth/round trip related optimizations in

IMAP/SMTP● QTLS (replacement for STARTTLS in SMTP)● IMAP SASL-IR● IMAP QRESYNC

Forward-without-download for encrypted content

● IMAP server can't do that, as it doesn't know the key

● Security implications are serious Do you trust your own IMAP server?

SIEVE

● Mail Filtering language, that can run in MTAs, MDAs, MUAs

● Selected items from the recently completed work: Sieve Extension: Variables Sieve Email Filtering: Vacation Extension Spamtest extension

Future SIEVE work

● Extended abilities to process/manipulate email messages Sieve Email Filtering: Body Extension Sieve Email Filtering: Editheader Extension SIEVE Email Filtering: MIME part Tests, Iteration,

Replacement and Enclosure

● SIEVE Email Filtering language - reject extension Needs ability to send UTF-8 error responses in

SMTP

● Sieve Extension: Notifications

Important Informational documents

● Internet Mail Architecture (draft-crocker-email-arch-05.txt)

● Deployment Considerations for lemonade-compliant Mobile Email (draft-ietf-lemonade-deployments-03.txt)