TLP Mail Marker by Mustafa Kamoona

Apply FIRST TLP 2.0 markings to email you compose in Roundcube Webmail. Choose TLP:CLEAR, TLP:GREEN, TLP:AMBER, TLP:AMBER+STRICT or TLP:RED, and add consistent subject and body markings before sending.

It can warn or block when a message has no classification, and warn when a reply or forward would lower the original classification. Settings let you choose approved levels, a default level, marking style and organisation profiles.

Works with Roundcube Webmail. Add your webmail hostname in Settings and approve access for that site, then reload webmail. No website access is granted at installation. This is not a Gmail or Outlook extension.

Email processing stays on your device. No developer servers, analytics, tracking or remote code. Only settings are stored locally. TLP labels communicate sharing boundaries; they do not encrypt email or enforce recipient behaviour.

Desktop Firefox 140+ is tested. Firefox for Android is untested.

Open-source under the MIT licence: https://github.com/mustafa-kamoona/tlp-mail-marker
Support: https://github.com/mustafa-kamoona/tlp-mail-marker/issues
Report vulnerabilities privately: https://github.com/mustafa-kamoona/tlp-mail-marker/security/advisories/new