What's new in the World IMAP/LEMONADE/SIEVE (no DKIM or EAI) Alexey Melnikov

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 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 (IMAP IDLE)  Quick Flag Changes Resynchronization (CONDSTORE)  Reduction of bandwith/round-trips

[Soon to be] completed work in IMAPEXT WG ● April Collected Extensions to IMAP4 ABNF (RFC 4466) ● October Comparators (Internet Application Protocol Collation Registry) - draft-newman-i18n-comparator-14.txt - in RFC editor queue ● October 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 IMAP4 ACL Extension (RFC 4314) ● Dec Update to UIDPLUS (RFC 2359), RFC 4315 ● Jun IMAP Extension for Conditional STORE Operation or Quick Flag Changes Resynchronization (RFC 4551) ● Apr IMAP CATENATE Extension (RFC 4469) ● May Message Submission BURL Extension (RFC 4468) ● May IMAP - URLAUTH Extension (RFC 4467)

Forward-without-download

Lemonade interop event October 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= /;UID=20 .;UIDVALIDITY= /;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 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 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 (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 Filtering: Vacation Extension  Spamtest extension

Future SIEVE work ● Extended abilities to process/manipulate messages  Sieve Filtering: Body Extension  Sieve Filtering: Editheader Extension  SIEVE Filtering: MIME part Tests, Iteration, Replacement and Enclosure ● SIEVE 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- -arch-05.txt) ● Deployment Considerations for lemonade-compliant Mobile (draft-ietf-lemonade-deployments-03.txt)