Thundermail beta separates email hosting from free apps

Thunderbird’s June 23, 2026 update renamed its subscription offering Thundermail after early invitation waves. Appointment and Send remained included services. The developers said the desktop and mobile applications remained free and compatible with other email services. The rename clarified the boundary between hosting an account and choosing a client application. ^[1]

The model came from an April 4, 2025 plan separating features delivered on a device from cloud services with storage costs. That announcement proposed initial paid subscriptions and a limited free tier only after a sufficient paying base could support it. The free-hosting tier was a conditional plan, rather than a confirmed offer. ^[2]

Mozilla’s IMAP reference explains part of that separation. Messages and folders remain on a server, with changes mirrored between it and Thunderbird. Downloaded messages can be used offline; later changes synchronise on reconnection. A desktop application provides a way to work with an account while a server maintains the remote mailbox. ^[3]

The services roadmap, updated August 4, 2026, classified multifactor authentication as shipped in June. It still listed webmail as active work on an experimental feature initially limited to folder visibility and message display. Those are developer-reported milestones, not independent performance testing; the roadmap itself warns that timelines can change. ^[4]

About this item: Retrospective report. No first-hand reporting or independent testing is claimed. Corrections policy.