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Product guide

How InboxSift sorts Gmail into Act, Know, and Noise

Importance and type are different questions. InboxSift answers both.

Gmail already sorts by date. InboxSift sorts by what the message asks of you. That is a model plus guardrails, not a magic unread badge.

Category vs type

Category is Act, Know, or Noise: how much attention you should spend. Type is newsletter, receipt, travel, school/work, social, and so on. A receipt can be Know. A newsletter can be Noise. A flight change can be Act and still be type travel.

What the classifier sees

For recent Inbox threads, InboxSift uses sender, subject, snippet, a clipped body preview, and bulk-mail headers (List-Unsubscribe, List-Id). That content goes to our classify API so a model can return a category and Briefing line. We do not pretend the model “never reads” the email.

Your overrides

Always Act / Know / Noise on a contact is a hard preference. Relationship hints (important vs automated) are a weak prior when the model is unsure—not a way to hide a real homework assignment.

Typical Act / Know / Noise examples

  • Act: “Please confirm Tuesday at 3,” homework assigned, bill to pay, permission request.
  • Know: Apple receipt, package delivered, meeting room changed, grade posted.
  • Noise: product roundups, “jobs picked for you,” kudos, class enrollment ads.

Where this runs

The Chrome extension calls /api/inbox-sift/inbox and /api/inbox-sift/classify. Results cache locally so Briefing feels instant on reopen. Full HTML loads per thread when you open it.

Frequently asked questions

Can classification be wrong?
Yes. Override the contact, or open the thread in Gmail. Briefing is a filter, not a court.
Does Noise mean deleted?
No. Noise is omitted from Briefing. The message stays in Gmail.

Sources & further reading

Published 2026-09-04. See also our full article library.

Get through your inbox faster

InboxSift sorts Gmail into Act, Know, and Noise so you can see what needs you and ignore the rest.

Free · Works in Gmail