Session Date/Time: 24 Jul 2025 12:30

mailmaint

Summary

The mailmaint working group met to discuss the status of documents approaching completion, updates on active drafts, and several new proposed work items. Key topics included finalizing UID batches and JMAP keywords drafts, OAuth profile specifications, EAI address formats, and several new proposals including MTA hooks, unobtrusive end-to-end signatures, and IMAP implementation recommendations.

Key Discussion Points

Documents Near Completion

UID batches: Completed working group last call with implementations in iOS, iCloud, and FastMail. Minor concerns from Alexi about batch size descriptions need addressing. Will issue one-week working group last call.
IMAP JMAP keywords: Gone through working group last call. Jim identified some issues during shepherding that need review. Will do short working group last call.
Wrong recipient URL: Waiting for implementations and security considerations updates from John. Discussion on what actions should be permitted after receiving wrong recipient notification.
Expires header: John will document existing implementations rather than create new "expires because" header based on feedback from mail providers.
Auto-config: Shepherd review identified need for significant work requiring another working group last call. Discussion on whether to specify XML format formally or use examples.

Active Drafts

OAuth profile: Neil proposed using RFC 9728 protected resource metadata to decouple from auto-config discovery. Discussion on semantic vs protocol-level scopes, with preference for semantic scopes like "mail", "contacts", "calendar".
PAC: Ben reported no changes since last IETF. Seeking working group feedback on direction.
EAI addresses: Aren presented two drafts - one for nice human addresses (restrictive) and one for liberal syntax. Key issues include choice of character repertoire (LGR vs UAX31 vs RFC8264), length limits, and handling of diacritical marks.

New Proposed Work

IMAP Implementation Recommendations: Rick proposed BCP-style document listing most effective IMAP extensions for clients and servers to implement. Based on developer discussions, focuses on widely-deployed extensions that provide immediate value.
MTA Hooks: Murilo presented JSON/HTTP-based replacement for Milter protocol for MTA filtering. Addresses Milter's undocumented binary protocol limitations. Deemed too large for mailmaint - should be BOF'd.
Unobtrusive End-to-End Signatures: DKG presented draft for invisible cryptographic signatures that don't break legacy clients or show scary warnings. Uses multipart/mixed structure with headers copied inside.
Web Push for IMAP: Simon updated proposal with JSON payloads and notify-like filters. Interest uncertain - needs list discussion.
Object ID Partial: Bron proposed simple extension allowing servers to advertise partial Object ID support.

Decisions and Action Items

Issue one-week working group last call for UID batches (pending Alexi's review)
Issue short working group last call for IMAP JMAP keywords
John to add security considerations text for wrong recipient URL
John to document existing expires header implementations
Ben to update auto-config draft addressing shepherd feedback
Neil to update OAuth profile with protected resource metadata approach
Call for adoption of IMAP implementation recommendations document
MTA hooks to be proposed as BOF for separate working group
DKG to send unobtrusive signatures draft to list for feedback

Next Steps

Multiple working group last calls to be issued next week
Contributors to read and review updated drafts
List discussion on interest levels for various proposed work items
Coordinate with other working groups (LAMPS, OpenPGP) on signature work
Develop BOF proposal for MTA hooks if sufficient interest exists