Postbox settings reference
Every Postbox behavior toggle in one place — auto-advance, reply defaults, density, writing suggestions, auto-summaries, notifications, the on-device cache, and the send sound — with what each does and its default.
This page is a reference for the per-user behavior settings under Postbox → Settings. They're preferences of the person, not of a mailbox, so they apply across every mailbox you have on this instance. Most live in the settings page's Reading section; a couple sit in their own cards below it. The feature pages (Postbox, Smart Inbox, Reply Queue) explain the behavior in context — this is the flat list of switches.
Changes save the moment you flip them.
Reading
| Setting | What it does | Default |
|---|---|---|
| After archiving, deleting or snoozing | What the reader shows once you triage the open conversation away — Open the next conversation, Open the previous conversation, or Go back to the list. See auto-advance. | Open the next conversation |
| Density | How tightly the message list and reader are packed: Comfortable (roomy) or Compact (tighter rows, single-line subject/snippet). | Comfortable |
| Default reply behavior | What the Reply button and the r shortcut do — Reply to the sender only or Reply to everyone (reply all). The a shortcut always replies to everyone, and you can switch a reply to reply-all while composing. | Reply to the sender only |
| Writing suggestions | Inline AI ghost-text autocomplete as you write; press Tab to accept. Only shown when the ai flag is on — this toggle is the per-user opt-out within an AI-enabled instance. | On (when ai is enabled) |
| Auto-summarize long threads | Show a one-line AI summary strip at the top of long conversations; click to expand the key points. Only shown when the ai flag is on. | On (when ai is enabled) |
| Play sound when sending | Play a short confirmation sound when a message is dispatched. | Off |
Writing suggestions and Auto-summarize long threads only appear when the instance has the ai feature flag enabled (with an LLM provider configured). The flag is the master switch; these toggles let an individual user opt out. See Feature flags.
On this device
The On this device card controls the optional offline read cache — a small, device-local, unencrypted copy of your recent mail so Postbox opens instantly and stays readable offline. Full details in Postbox → Offline & local cache.
| Setting | What it does | Default |
|---|---|---|
| Store recent mail on this device | Keep the newest inbox rows and recently-read bodies (already sanitized) in this device's local database. | On in the desktop app, off in the browser |
| Clear local cache | Wipe this device's cached mail immediately. Not a toggle — a button. | — |
The on-device cache is unencrypted local storage. Turn Store recent mail on this device off (or clear it) on any machine you don't control.
Notifications (desktop app only)
The Notifications card only appears in the desktop app, where Postbox can fire native OS notifications and drive the dock/tray unread badge.
| Setting | What it does | Default |
|---|---|---|
| Notify me about | Which new inbox mail pops a native notification — Everything, People & important only, or Nothing. "People & important only" uses Smart Inbox categories to stay quiet about newsletters and automated mail (mail not yet classified still notifies, so nothing is dropped before the classifier runs). | People & important only when smart categories are live (the ai flag is on); otherwise Everything |
| Count all mail in the badge | Whether non-people mail still increments the dock/tray unread badge. Turn it off to keep the badge count focused on people & important mail even while notifications are quiet. | On |
Related settings pages
A few Postbox settings live on their own pages rather than as simple toggles:
- Snippets — manage
/-triggered canned responses. - Writing voice (needs
ai) — teach AI drafts to sound like you, learned from your sent mail. - Signatures, Filters, Aliases, Forwarding, Vacation, App passwords — covered in the Postbox guide.