Does an AI Email Assistant Store Your Email?

Not the message body. Insulin’s Inbox app fetches each email body from Gmail or Outlook when you open the message, and the full body is never stored — but it does keep a short, specific list of other things, and a security review should know every item on it.

Updated October 8, 2026: the Inbox documentation now lists a Customer snapshot among what Insulin keeps, and describes saving and sending Gmail drafts from Mails ▸ Drafts, which Insulin does only when you press Save or Send. The inventory, the mailbox-writes list, the FAQ and the takeaways below are updated to match; the mailbox-writes list also adds the gmail.modify permission that draft copies, labels and stars in Gmail depend on, and the section on models now notes that Inbox can also use AI providers its settings card does not list.

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Connecting a mailbox is where a privacy review leans in, and the first question about any AI email assistant is the same: will it keep a copy of our mail?

Insulin’s Inbox sharpens the question, because its Mails view mirrors your mailbox — Inbox, Starred, Sent and Drafts — inside the workspace. A mirror is not necessarily a copy. The answer has two halves: a clean no for the body of every message, and a short list of what is kept instead. The list is the useful half, because each line of it can be checked against a data policy.

Does Insulin store the body of your email?

No. Email bodies are fetched live from your provider each time you open a message, and the full body is never stored by Insulin.

A fetched-live body is one read from Gmail or Outlook at the moment you open the message, rather than from a copy Insulin keeps. The mail list shows the short preview line your provider returns with each message; the body itself comes from your provider every time you open it.

What does Insulin keep while a mailbox is connected?

Per message: header fields, a preview line, labels, AI output, a Customer snapshot when a draft was written with a customer lookup, and records of which rules ran. Across messages: a writing-style profile, a History entry for each sent email, and the chat rail’s conversation. Exactly:

Item	Fetched live or retained	Exactly what is retained
Message body	Fetched live, each time you open the message	Nothing — the full body is never stored
Header fields	Retained	Subject, sender, recipients, timestamps
Preview line	Retained	Your provider’s preview (Gmail’s snippet, Outlook’s body preview), which is what the mail list shows
Labels	Retained	The labels applied
Extraction	Retained	Any structured extraction, for example a drafted reply’s subject and body
AI drafts	Retained	The drafts themselves and their edit history
Customer snapshot	Retained when a draft was written with a customer lookup; an auto-sent reply carries none	Which of your Fours customers the sender was matched to, and a summary of that customer’s entitlements, offers and invoices, taken when the rules ran — “what the AI knew when it wrote the draft, not today’s figures”
Thread summary	Retained when you request one	The summary
Rule traces	Retained	Records that explain which rules ran
Writing style	Retained	A profile learned from your recent sent mail, summarized as your greeting, sign-off, register, and common openers and closers
Approvals ▸ History	Retained	Per sent email: the subject, the recipients, and who authorized it and when
Inbox chat rail	Retained	Your conversation with the agent, on a thread separate from your Chat history

The table records what is kept, not where or for how long. Settle those two in your contract review rather than assume them.

Is what Insulin keeps just metadata?

No. Beyond routing data, five kinds of retained text come from the message or are derived from it, and a data inventory should record them as content:

• The subject line, written by whoever sent the message.
• The preview line, which is text from the message. Microsoft’s API reference defines Outlook’s body preview as the first 255 characters of the message body.
• An extraction, which can hold a drafted reply’s subject and body.
• An AI draft, a reply to the message, kept with its edit history.
• A thread summary, which condenses the thread and exists only when you ask for one.

The Customer snapshot is a different kind of record. It holds which of your Fours customers the sender was matched to, and that customer’s entitlements, offers and invoices as they stood when the rules ran, so a data inventory should record it as customer data from your Fours account rather than as message content.

So the precise sentence for a security questionnaire is not “the assistant stores no email.” It is: the full body is never stored; metadata, the provider’s preview line, AI output about the message and a snapshot of the customer the sender was matched to are. Every clause of that can be verified, which a blanket denial cannot.

Which model works on your mail?

The first available one in your chain: your connected model providers first, Fours’ hosted models as the last resort. Never storing a body is not the same as never processing mail — classification, tagging, drafting a reply, summarizing a thread and building your writing-style profile are model work, and Inbox runs it on the same chain of candidate models the chat agent uses.

Settings → Account → AI model lists five providers — Claude Code, Codex, Anthropic, OpenAI and Gemini — and shows Connected or Connect for each. Inbox can also use other AI providers you have connected yourself, even though that card does not list them. With none of your own connected, Inbox runs on Fours’ hosted models and the card says so. If your organization does not allow hosted models either, rules are not interpreted and no draft is produced.

Two more boundaries: the writing-style profile is used only for draft generation and never leaves your tenant, and Inbox only ever reads the knowledge bases you attach — it never adds to or changes one. Training is a separate question, covered in whether your company data is used to train models.

What does Insulin write into your mailbox?

Very little, and the documentation states it as a limit:

• Drafts, on Gmail only. Insulin mirrors each AI draft into your Gmail Drafts folder, creating it when the reply is generated, updating it when you edit, and deleting it when you send or archive from Inbox. Those drafts are the only messages Insulin creates in your mailbox. Outlook drafts are not mirrored.
• Draft edits and sends, on your action. On Gmail, Mails ▸ Drafts opens any draft in your Gmail Drafts folder — yours or one Inbox mirrored — in a composer. Save writes your edits back to the draft in Gmail, and Send asks you to Confirm send (“This sends from your mailbox immediately.”) before the draft goes out. Inbox never sends a mailbox draft on its own.
• Labels and read state. On mail you received, Insulin changes only labels and read state — never the message content — and it never deletes one. On Gmail, the labels your rules declare sync as real Gmail labels.
• Replies, only on your say-so. A reply goes out from your mailbox when you press Send and confirm, or when an auto-send rule you wrote yourself fires. When the Inbox app acts, and when it asks covers where that line is drawn.

On Gmail, the draft copies and the labels and stars Inbox mirrors all need your Gmail connection to carry Gmail’s gmail.modify permission. Without it nothing is copied to Gmail, but Inbox itself works as before: drafts still wait in Approvals ▸ Pending, and labels and stars still show in Inbox.

What should a security review record?

That the body is never stored, that every other row of the inventory is retained, and that five kinds of retained text are content — not “no email data.” Before you connect a mailbox:

1. Classify the subject and preview lines, extractions, AI drafts and thread summaries as message content, and the Customer snapshot as customer data.
2. Check which AI providers you have connected, including any Settings → Account → AI model does not list, or whether Fours’ hosted models will do the work.
3. Know the exit first: what Disable and Disconnect do to your mail walks through it item by item.

Frequently asked questions

Does Insulin store the full text of my emails?

No. Email bodies are fetched live from Gmail or Outlook each time you open a message, and the full body is never stored. Insulin does keep other items, including the subject, sender, the provider preview line and its own AI drafts.

What does Insulin keep about each email?

The subject, sender, recipients and timestamps; the provider preview line; the labels applied; any structured extraction; the AI drafts and their edit history; the Customer snapshot, when a draft was written with a customer lookup; a thread summary if you request one; and rule-trace records of which rules ran.

Is the preview line part of the message text?

Yes. It is the short preview your provider returns with each message, the Gmail snippet or the Outlook body preview, and it is what the mail list shows. Microsoft defines the Outlook body preview as the first 255 characters of the message body.

Does Insulin change or delete mail in my mailbox?

It never deletes mail you received, and on that mail changes only labels and read state. On Gmail it creates, updates and deletes its own AI drafts, and saves or sends a draft in Mails ▸ Drafts only when you press Save or Send. Outlook drafts are not mirrored.

Which AI model works on my mail?

Your connected model providers, in order, with the hosted models Fours provides as the last resort. Classification, tagging, drafting, thread summaries and the writing-style build all walk that chain. With no provider of your own connected, Inbox runs on those hosted models.

Takeaways

• The full body of an email is fetched live from Gmail or Outlook and never stored.
• Never storing the body is not storing nothing: every other row of the inventory is retained.
• Five kinds of that retained text are message content, and the Customer snapshot is customer data. Classify each that way.
• Storage is not processing: model work runs on your connected providers first and Fours’ hosted models last.
• In your mailbox, Insulin creates only its own Gmail drafts and, on mail you received, changes only labels and read state. From Mails ▸ Drafts, it saves or sends a Gmail draft only when you press Save or Send.

An AI email assistant earns a mailbox connection by being exact about what it keeps. See how the Inbox app drafts replies and labels mail for your review, while the full body of each message stays with your provider.