I feel we are talking about two different things here. I do not agree with the merge of these topics. Is very clear that prevails the Title of the one that suggest and App, and that goes beyond and far than the other idea, which is more realistic.

The Concept: Visual Structure for Complex Workflows
While a traditional list view is perfect for quick replies, it fails to provide the structural overview required for multi-stage professional processes. I am proposing a native Kanban Board View that allows users to transform any folder, label or scenario into a visual pipeline.

The "Why": Managing the Fragmented Inbox
Even when using dedicated professional platforms (such as Indeed for hiring, Jira for dev-ops, or a CRM for sales) the final mile of communication always lands in the Inbox.
Currently, these "notification-heavy" processes lead to a cluttered list where it is difficult to see the email status of a specific thread at a glance. Instead of clicking through dozens of emails to remember where a candidate or a project stands, a Kanban Board View provides immediate spatial organization. This isn't about replacing specialized platforms; it’s about providing a superior way to manage the communication generated by them.

The Proposed Structure: "The Action Pipeline"
Instead of "To-Do," the default columns should reflect the status of a communication lifecycle:
• Incoming / Triage: The default landing zone for new, unclassified mail.
• Active / In-Progress: Emails requiring research, drafting, or internal coordination.
• Awaiting Response: A dedicated column for "the ball is in their court," preventing threads from being buried.
• Follow-up Required: High-priority items that need a second touchpoint.
• Completed / Closed: Successfully resolved threads.
• Custom Columns: Users should be able to create, rename, and reorder columns to match their specific needs (e.g., a "Hiring" board with columns: Applied, Screened, Rejected, Interviewing, Offered).
• Folder/Label Integration: Each column should ideally map to an existing Folder or Label. Dragging a card to a new column automatically updates the email's label or moves it to the corresponding folder.

Automated "End-of-Life" Actions
A critical component of this feature is defining what happens when an email reaches the final column (e.g., Completed / Closed). The board should offer configurable "Exit Actions":
1. Auto-Archive: Automatically move the email to the Archive to keep the board clean.
2. Mark as Read: Ensure the thread no longer triggers notification counts.
3. Delete/Trash: For ephemeral workflows like temporary inquiries.
4. Stay in Place: Keep the card visible for record-keeping until manually cleared.
5. Other

How it Works (The MVP Approach)
1. Toggle-able View: Users can switch between "List View" and "Board View" for any specific folder, label or section.
2. Manual & Automated Assignment: Emails stay in a "No-Board" or "Inbox" state by default. Users can manually drag-and-drop a thread into a column, or set up Sieve filters to automatically route specific senders (e.g., no-reply@indeed.com) to a specific board column.
3. No External Dependencies: This remains a native, integrated feature of Proton Mail, ensuring a seamless and fast user experience without third-party management.

Why this is essential for Professionals:
Whether it is a recruitment drive, a procurement cycle with multiple vendors, or managing client inquiries, a Kanban structure allows for a "birds-eye view" of a professional’s workload. It turns the inbox from a simple message repository into a structured management tool.