KeepKnown is an advanced filter builder designed for Gmail and Outlook, acting as the ultimate upgrade your native inbox filtering should have. Built to handle complex inbox organization, KeepKnown lets users combine relationship, history, header, attachment, subject, and mailbox signals using powerful nested logic.

Designed with security and testing in mind, core filtering does not read email bodies. Users can preview rules on real mail, trace every single match via a transparent decision log, and safely activate rules in Shadow, Review Only, or Enforce modes where supported. Additionally, new filters are saved paused by default, and reusable templates help speed up common daily workflows.

Pros of KeepKnown

Advanced filter builder for both Gmail and Outlook
Supports nested logic combining relationship, history, header, attachment, subject, and mailbox signals
Core filtering does not read email bodies, enhancing privacy
Safe testing and deployment with Shadow, Review Only, or Enforce modes and a comprehensive decision log
Reusable templates and paused-by-default filter creation for efficient workflow management

Cons of KeepKnown

Requires proper mode configuration (Shadow, Review Only, Enforce) depending on supported platforms
New filters save paused by default, requiring manual activation
Specific email body parsing is intentionally excluded from core filtering

Frequently Asked Questions

Which email providers does KeepKnown support?

KeepKnown is built as an advanced filter builder specifically for Gmail and Outlook.

Does KeepKnown read the content of my emails?

No. Core filtering in KeepKnown does not read email bodies, protecting your email privacy.

How can I safely test new filters before turning them on?

You can preview rules on real mail, use a detailed decision log to trace every match, and activate rules in Shadow or Review Only modes before enforcing them.