Mozilla is launching a new email service called Thundermail, which will be part of the Thunderbird Pro platform, aiming to compete with Gmail and Microsoft 365. The service will offer features such as scheduling tools, AI-powered writing assistance, and email hosting. Thundermail will use the open-source Stalwart stack and will allow users to choose between thundermail.com and tb.pro domains. The service is expected to be paid, with free tiers having limitations such as less storage.