diff --git a/README.md b/README.md
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--- a/README.md
+++ b/README.md
@@ -1,16 +1,51 @@
 # govoplan-mail
 
-GovOPlaN Mail module.
+GovOPlaN Mail is the mail transport module. It owns reusable SMTP/IMAP profile management, mail profile policy enforcement, mock mail infrastructure, and the mail WebUI package.
 
-This repository owns the Mail module manifest, backend router, mail schemas, mail profile ORM model, SMTP/IMAP profile services, SMTP/IMAP adapters, development mailbox backend, and mail profile WebUI package. The remaining `app.*` imports are transitional core adapters for auth, governance settings, secrets, and legacy access models.
+## Ownership
+
+This repository owns:
+
+- backend module manifest `mail`
+- mail permissions such as `mail:profile:read`, `mail:profile:write`, `mail:profile:use`, and `mail:profile:test`
+- SMTP/IMAP profile models, policy checks, encrypted credential storage, and profile resolution
+- SMTP send and IMAP append adapters, including mock transports for development
+- development mock mailbox endpoints used by test-send flows
+- WebUI package `@govoplan/mail-webui` with profile and policy management components
+
+Core owns auth, tenants, RBAC evaluation, database/session primitives, secret helpers, CSRF/API helpers, and shell layout.
 
 ## Development
 
-Install through the core development environment:
+Install through the core environment:
 
 ```bash
 cd /mnt/DATA/git/govoplan-core
 ./.venv/bin/python -m pip install -r requirements-dev.txt
 ```
 
-The backend module is registered through the `govoplan.modules` entry point `mail`. The frontend package is `@govoplan/mail-webui`.
+Run the WebUI from the core host:
+
+```bash
+cd /mnt/DATA/git/govoplan-core/webui
+PATH=/home/zemion/.nvm/versions/node/v22.22.3/bin:$PATH /home/zemion/.nvm/versions/node/v22.22.3/bin/npm run dev
+```
+
+## Module integration
+
+Backend entry point:
+
+```toml
+[project.entry-points."govoplan.modules"]
+mail = "govoplan_mail.backend.manifest:get_manifest"
+```
+
+Frontend package:
+
+```text
+@govoplan/mail-webui
+```
+
+The campaign module depends on this module for sending, append-to-Sent behavior, profile selection, and upcoming read-only mailbox inspection.
+
+Platform RBAC and governance rules are documented in `govoplan-core/docs/`.