Sender Smart Categories: Reuse and Subject Checks

Sender Smart Categories can reuse a saved sender-to-category assignment instead of asking the model again. This reuse has eligibility conditions; it does not mean all future messages from an address have the same purpose.

Which categories can be cached?

The current processor permits categories whose primary action is Move or Delete. Keep categories are not eligible for cached routing. A saved assignment still needs the subject guard to pass before reuse.

The guard normalizes subject words, ignores numbers and common reply prefixes, and compares learned patterns. An unrelated subject can cause individual classification. An empty or digits-only subject, or missing stored patterns, instead permits a match fallback. This is a heuristic, not a guarantee that changed message types are detected.

Review mixed-purpose senders

Test an invoice and a promotional message from the same fictional address. Inspect actual categories before applying moves. Review existing saved assignments as well as the setting for automatic categorization of new senders; do not treat a setting change alone as proof that every stored decision is bypassed.

The direct subject-guard checks show the observed code behavior with synthetic inputs. They are not a model accuracy benchmark or a live mailbox test.

Keep actions reviewable

Start with a dedicated folder and inspect new subjects. A cached assignment cannot correct an unclear category prompt. See multi-action controls and History and Undo for the recovery limits.