Inbox

Inbox is an email-triage workspace that connects your mailbox, sorts incoming mail into your own categories, and drafts replies in your writing style — plus rules that can react to a CRM event. Nothing leaves your mailbox until you approve it.

What Is Inbox?

Inbox is a built-in Insulin app pinned to the desktop Dock. Once you connect a mailbox, Insulin watches for incoming email, categorizes each message, and — when a rule matches — produces something for you: a drafted reply, a Slack notification, or a CRM action. Everything it produces waits in a Needs approval queue where you read, edit, and confirm it.

Prefer video? Watch a quick overview:

The whole feature is built around one safety promise:

Opening the Inbox App

Open Inbox from the Inbox tile pinned to the desktop Dock, or from the Search apps… launcher in the System Bar. Like other workspace apps it opens as a resizable window.

A left sidebar navigates the app:

Mails opens on Inbox. The Categories group appears only once you have created at least one category, and picking a category shows every mail carrying it across all statuses. Archived is the user-facing name for mail you dismissed — it is kept, not deleted.

How an Email Becomes an Action

Everything on the solid path stops at Needs approval. The two dashed outputs are the exceptions: a Slack notification only tells you something happened, and auto-send exists only if you wrote a rule that asks for it.

Connecting a Mailbox

Open Settings → Account and find the Email source section. Inbox does not run its own OAuth flow — it reuses the connection you set up under Integrations.

Each provider has its own card, and there are two paths to enabling it:

1. Already connected — If you have already connected Gmail or Outlook through Integrations, the card shows an Enable Inbox for Gmail / Enable Inbox for Outlook button. Clicking it health-checks your access, registers the mailbox webhook, seeds your categories, and starts building your writing style.
2. Not connected yet — The card shows a Connect Gmail / Connect Outlook link that takes you to Settings → Integrations, where the standard connection lives. Once connected, return to this page and click Enable Inbox for ….

A connected card shows Connected as your mailbox address, plus an Inbox enabled badge once Inbox is running.

Account Lifecycle

The active provider’s card exposes two lifecycle controls with very different effects on your data:

Switching between Gmail and Outlook

When one provider is active and the other is already connected under Integrations, the inactive card offers Switch to Gmail… / Switch to Outlook….

If you disconnect the integration itself

Disconnecting the underlying Gmail or Outlook integration (under Settings → Integrations, outside Inbox) does not purge your Inbox data immediately. Insulin starts a 7-day grace period: reconnect the integration inside that window and nothing is lost. If the integration is still missing after seven days, the stored email records are hard-deleted and Inbox resets to a never-connected state.

Needs Approval

Needs approval is the queue of everything Inbox has produced for you and is holding until you act. It is the tab Inbox opens on, and the sidebar badge counts what is waiting.

Use the search box to fuzzy-search the queue, and the rule filter beneath it to narrow to one rule’s output.

Reviewing a drafted reply

Selecting a reply draft opens a compose pane on the original thread:

• To is editable, and a chevron next to it reveals a Cc field so you can copy other people on the reply. More ▸ Reply all pre-fills Cc with the thread’s wider audience (minus yourself).
• The thread history sits above the editor so you can read what you are replying to.
• The reply body is inline-editable and saves when you click away from the field.
• Attach stages files onto the reply.

Sending is a two-step gesture. Clicking Send opens a “Send this reply?” confirmation dialog, and you must confirm there before the reply actually goes out. This second step exists because sending is irreversible — there is no unsend or recall.

Reviewing a new outbound draft

A rule fired by a CRM event — or a draft the AI chat rail created for you — produces a brand-new email rather than a reply. That one opens as a compose pane with an editable To, Subject, and Draft body, and the same Save / Send / Archive actions. The confirmation dialog reads “Send this email?”.

Running a CRM action

A rule can also produce a CRM action — a written instruction such as “update the CRM with a short summary of the latest email thread.” It appears in the queue as its own block showing the instruction and a Run in chat button.

Attachments

Mails

Mails is the browsable record of everything Inbox has processed. Pick one view at a time from the sidebar:

The page has three panes: a searchable mail list, a conversation view, and the AI chat rail.

The conversation view shows the subject once, the number of messages, the categories applied to it, and a status badge. Older messages in the thread are collapsed and load when you click them.

• Archive / Unarchive sit in the conversation header, because they act on the whole conversation.
• Reply, Reply all, and Forward sit under the newest message. If Inbox has already drafted a reply for that mail, Reply takes you straight to that draft in Needs approval instead of opening a blank composer.
• In the reply composer, AI generate writes a draft in your learned writing style, which you can then edit before sending.

The Inbox Chat Rail

Every Inbox page carries a chat rail down the right-hand side, headed Chat with your inbox. It is not the Chat app in a narrow window — it is a conversation about the mail you are looking at.

• It is always there. Every page — Needs approval, Mails, Rules, Account, Categories — mounts the same rail. Collapse it with the button in its header; a small reopen button then appears at the top-right of the page.
• It resizes. Drag the handle on its left edge. The rail can be anywhere between 15% and 45% of the window width; it starts at about 30%.
• It has its own conversation. The rail runs the built-in Insulin agent on a thread dedicated to Inbox, separate from the Chat app — so your inbox conversation never mixes into your general chat history. Type /clear to start a fresh one.
• It knows what you are looking at. Every message you send carries the current page as context: which tab you are on, which category is selected, which mail is open, and the mails currently visible in the list. Ask “what needs a reply here?” and it answers about the screen in front of you, not about your mailbox in the abstract.
• It can act. Beyond reading, listing, searching, and counting your mail, the agent can create an email draft for you (it lands in Needs approval like any other draft) and create a rule from a plain-English description. It is also where a Run in chat CRM action executes.

Rules

Rules control what Inbox does for you — which messages get a drafted reply, which CRM events produce work, and what context the AI pulls in. Open Settings → Rules.

The left panel lists your rules in two groups — Default (rules Suger ships) and Custom (yours) — with a search box and a New button. Every row carries an enable switch and a delete button, so turning a rule off never requires opening it.

Describing a rule

The rule editor is natural-language first. There are only two fields:

1. Rule name — optional. Leave it blank and Insulin generates one for you.
2. Describe the rule in natural language — a plain-English box where you say what should happen, for example “When a new email arrives that needs a reply, draft a reply for me to review before it is sent.”

Then click Save. That single click both turns your description into a structured rule and saves it — there is no separate generate step. Saving runs an AI model and takes a few seconds; an inline notice asks you not to refresh while it works.

Editing a rule works the same way — change the description and click Save again. Changing only the name just renames it; the rule’s behavior is left alone.

Starter hints on a new rule

A brand-new, still-empty rule shows a hint block under the buttons, which disappears as soon as you type anything.

The top strip spells out the shape of every rule — Trigger → Integrations → Output:

Below it, four Try an example chips fill the description box with a ready-made prompt you can edit before saving:

• Salesforce stage → email + Slack
• New email → drafted reply
• HubSpot deal won → welcome email
• Dynamics stage → CRM action

Details

Details opens a read-only view of the structured rule your description produced: the Trigger, the Filter (or, for a CRM rule, the stage / amount / owner it matches), the Context sources it may search, the Generation inclusions and exclusions, and the Actions it routes to. You can open the Trigger and Context-source pickers to browse what is supported, but nothing there is editable — to change a rule, change its description and save again.

Details is unavailable on a brand-new draft (nothing has been generated yet) and becomes available once the rule is saved.

Actions

Every rule routes its outcome to one or more action cards:

The two Email reply modes are mutually exclusive — a rule drafts for review or sends automatically, never both.

The default rule

Inbox ships one rule under Default, to show what the system can do. When an email arrives, it checks whether the mail needs a reply and generates a draft for you to review in Needs approval. It cannot be edited — use the switch on its list row to turn it on or off, or delete it outright. Deleting it leaves your own rules untouched.

Triggers: reacting to a CRM event

A rule does not have to start from an email. Under Settings → Account → Triggers, Inbox lists the CRM sources it can react to:

All three are live. Each row is driven by your own user-level connection to that CRM, so:

1. Connect the CRM first. A row you have not connected shows Connect, which takes you to Settings → Integrations — see Salesforce, HubSpot, or Microsoft Dynamics 365.
2. Click Enable on the row. The row then shows an Enabled badge.
3. Write a rule that describes the CRM event you care about, in Settings → Rules.

Turning a trigger off with Disable keeps your rules: they stay saved and go dormant until you enable the trigger again.

Categories

Open Settings → Categories to manage the categories Inbox puts on your email. There are no built-in categories — every one of them is yours.

Create one with Add category, then give it:

• a Name (up to 40 characters), and
• a Description (up to 280 characters).

The description is the prompt the classifier reads to decide whether to apply the category to an incoming email, so describe the messages it should match specifically — vague descriptions produce false positives. Both fields are required to save.

Each category becomes an entry under Mails ▸ Categories, so you can browse everything it has been applied to.

AI Model

Inbox needs one working AI model to classify mail and draft replies. The AI model section of Settings → Account lists the model providers Inbox can use — Claude Code, Codex, Anthropic, OpenAI, and Gemini — and shows Connected or a Connect link for each. A credential whose sign-in has lapsed shows Reconnect instead.

Connecting and disconnecting model credentials happens on the Integrations page; this card only reports the state and links you there.

Writing Style

Insulin learns your writing style from your recent sent mail so AI drafts sound like you. It is shown under Settings → Account → Writing style, is used only for draft generation, and never leaves your tenant.

The card reports one of four states:

A build starts automatically when you enable Inbox, and Re-generate rebuilds it from your latest sent mail at any time — including out of a stuck or failed state.

Knowledge Bases

Attach knowledge bases to Inbox and it will consult them while drafting replies — useful for product documentation, canned answers, or a support playbook, so drafts draw on your actual material instead of improvising.

Open Settings → Account and find the Knowledge bases section. Tick a knowledge base to use it when drafting; untick it to stop. The list shows every knowledge base you can reach, including organization ones shared with you. Leave everything unticked and drafts are written exactly as before, with no knowledge base context.

Inbox only ever reads a knowledge base — there is no Read/Edit choice here, and Inbox never adds to or changes one. (The built-in Insulin assistant has its own separate selection, which can be granted edit access — see Knowledge Bases.)

The attached knowledge bases are searched for both reply modes — drafts that land in Needs approval and rules that send automatically. The one exception is a rule with pinned canned text: that text is sent verbatim without involving the model, so no knowledge base is consulted.

Use Cases

• Sort your mail your way — Write categories that describe the mail you actually get, and browse each one under Mails ▸ Categories.
• Faster replies in your voice — Approve AI-drafted replies that already sound like you instead of writing from scratch.
• Follow up when a deal moves — Enable the Salesforce, HubSpot, or Dynamics 365 trigger and write a rule that drafts the follow-up email the moment an opportunity changes stage.
• Keep the CRM current — Add a CRM action to that rule, then click Run in chat to watch the agent apply it.
• Hands-off acknowledgements — Author a rule that sends automatically with a canned reply, to acknowledge a specific class of email without review.
• Ask about your inbox — Use the chat rail to triage out loud: “which of these need a reply today?”