The correspondence is part of the system.

A finance team spends much of its day in correspondence, so the communications tools are part of the system and do not link out to anything else. Four modules make up this side of the platform, and each one reuses the same house controls as the ledger screens.

Email. A full mailbox over the existing mail store across all four catalogs:

• folders, search by scope, and a list state of six values that travels with the reader, so completing an action returns them exactly where they were;
• sender HTML sanitised and rendered inside a sandboxed frame, with the block defaults the sanitiser removed supplied back, so a message reads as its author intended without its scripts;
• translation into any of the five interface languages, above the message body;
• compose with drafts, address search, AI drafting and refinement, and filing to an account with reusable filing rules;
• an attached invitation parsed and used to pre-fill a calendar entry without writing anything.

Messaging is app-to-app chat between people in the same entity, with one-to-one and group threads, attachments, read state, pinning, muting and archiving. Delivery is live over server-sent events, with replay from the last event the browser saw, so a reconnection never duplicates a message. The realtime transport was written in-house because the project does not add packages.

Notifications are built as a platform. Publishers raise an event, and a sweep running every minute claims each delivery atomically, so two running instances can never send it twice. Web Push is implemented directly against the framework's own cryptography, following the published standards, for the same no-new-package reason. Read, actioned and dismissed are kept as three separate facts, because they answer three different questions.

Planner and notes complete the set.

• The planner carries month, week and fortnight views, assignment to colleagues, reminders driven by a background sweep, attached documents, recurrence expanded in memory instead of written as rows, and full-content search.
• Notes is a secure per-account store on a four-level tree. Its original encryption was reverse-engineered, so legacy secure notes can now be both read and written. It also closes three data-exposure defects from the previous system structurally: the access check is part of every read, so nobody has to remember to call it.