Supermail Archive Insights

What it is

Archive Insights tracks the emails you archive in Supermail — whether you opened them first, and how long you spent — and surfaces the senders and subject lines you keep archiving (especially the ones you never open) — the mail you are effectively filtering by hand, and could turn into a real auto-archive Filter. It is the passive, behavioural counterpart to Supermail's rule-based Filters and its AI-powered AI Filtering: those act on incoming mail; this one watches how you actually triage and points out the patterns.

On by default, with three switches in Supermail Settings → Inbox → Archive Insights — the master tracking switch, the filter-nudge switch, and a "track time spent per email" (dwell) switch. All data stays on the device — no backend, no cost.

Where to find it

Inside Supermail's own Settings → Inbox → Archive Insights, which holds the master switch and its two companions.

How it behaves

How it works

• One capture point. Every archive gesture (list, swipe, bulk, in-thread) funnels through inbox-store.archiveThreads; each archive is recorded tagged with whether the thread had been opened (wasRead). Automated filter-archives take a different code path (api.archiveThreads directly) and are never miscounted.
• Time spent (dwell). A small order-independent open-tracker records how long a thread was open; when you archive the thread you were reading, the event carries that duration (capped to bound idle-tab inflation), so quick-glance-then-archive senders stand out.
• Undo-safe + off the hot path. Events are buffered in memory and flushed to IndexedDB only after the ~10s undo window, so undoing an archive drops them before they persist; capture is error-isolated and never blocks or affects the archive itself.
• Grouped for you. A pure aggregator groups events by sender, sender domain, and a normalized subject (folding Re:/Fwd: and templated tails), with counts, a date range, the opened-vs-never-opened split, and the average time-open. The view filters between All / Never opened / Opened-then-archived.
• One-click filter. Each row — and the nudge — opens the Filter editor pre-seeded with an "auto-archive mail like this" rule for you to confirm (never a silent save).
• Proactive nudge. Keyed on the never-opened signal only: after you archive-WITHOUT-opening from the same sender a few times, a dismissible, rate-limited toast offers to create that filter on the spot (opened-then-archived doesn't push it).
• Private + bounded + encrypted. Sender/subject data is device-local and encrypted at rest (AMC's safeStorage keyring via a desktop-only, domain-tagged bridge that can decrypt only its OWN data — never another secret), retained long-term (~10 years, up to a generous row cap) so it's banked for future analysis, logged only through the PII-redaction logger, and a "Clear history" action wipes it.

Access the view at /archive-insights — from the command palette ("Archive Insights") or the Settings launcher. Code + tested invariants: src/plugins/supermail/ui/src/features/archive-insights/ (see its README.md).

Privacy

The store + nudge state are scoped per signed-in account (archiveDbNameFor(currentIdentity())), so separate people sharing one machine profile never share a store; a one-time, verified, non-destructive migration folds any legacy unscoped data into the current account. Everything is device-local and never sent to a server. The sensitive sender/subject fields are also encrypted at rest with the OS keyring — reusing AMC's credential-encryption engine through a scoped, domain-tagged (AIV1|) renderer→main bridge that can decrypt only its own data, so it can never be an oracle for another AMC secret. Invariants: supermail-archive-crypto-contract.md.

Known limitations

A row written while the OS keyring is momentarily unavailable is stored in plaintext until the one-time upgrade re-encrypts it on a later load; a row that can no longer be decrypted (the profile's keyring changed, or the store was copied to another machine) is dropped from the view — the at-rest property means unreadable ciphertext stays unreadable, never surfaced as an error.

Related

The AI Digest turns this data into concrete cleanup suggestions; Supermail AI Filtering is the rule-driven counterpart that acts on mail as it arrives.