Is Signal Spam safe?

Signal Spam hashes the hostname of every HTTPS page you visit and sends it to signal-spam.fr every 5 seconds for phishing checks.

Beyond reporting spam from supported webmail sites, the extension monitors navigation across all websites: it strips and XXH64-hashes each visited hostname and POSTs the hashes to vrf01.signal-spam.fr roughly every 5 seconds (a feature called SurfSafe, on by default). When a page matches its phishing database or an error occurs, it also sends the full URL plus a persistent random ID. When you report an email, the full message (headers, body, and links) is base64-encoded and sent to www.signal-spam.fr along with your webmail account credentials, and on some providers a page-injected script captures the webmail authorization token to fetch the raw message.