SeventyMail
Only the text you ask to process leaves your computer, when you click. It goes through the Seventy Labs server (hosted in Europe) to the chosen provider (Anthropic or OpenAI, United States) and back to Thunderbird. Seventy Labs never stores or logs it. The providers do not train on it and keep it at most 30 days for abuse detection, under their API terms. Your signature and quoted text are not sent unless you enable it.
Purchase: email address and country. Licence: a random device ID, extension and system version, approximate country. Credits: date, token count and amount for each operation, never the text. Your own API key stays on your computer and is never stored on our servers.
Ask for access, correction or deletion of your data at info@seventylabs.ch.