Mailbird is a desktop email client for Windows that connects to existing mail accounts. The vendor says mail is stored on the user's own computer rather than on Mailbird's servers. It also offers an optional AI feature that stays switched off until the user turns it on, and the client can block tracking pixels and remote images in messages. The software runs as a program installed on the user's own machine.
Mailbird Inc. is a company based in the United States, and its privacy policy names a controller address in Sacramento, California. The policy, last updated in 2018, says personal data is stored at and processed by the company, its affiliates and other third parties, including in the United States, and it names analytics tools in its cookie section. Because the mail itself stays on the device according to the vendor, the main sovereignty question concerns account, usage and analytics data, which is processed under US jurisdiction. For a European organisation, the client is a self-installed program whose vendor is subject to US law.