1 day Ago By Thomas Claburn
Thunderbird, Firefox maker Mozilla's open-source email client, is aiming to reinvent itself as a more comprehensive communications platform. Toward that end, the development team is in the process of rolling out a set of adjacent services, some of which may eventually bring in revenue. The storm bird's ecosystem expansion campaign represents an effort to counter the gravitational pull of commercial services including Google's Gmail and Microsoft Office 365, which have been peeling off Thunderbird users bit by bit.
"Thunderbird loses users each day to rich ecosystems that are both clients and services, such as Gmail and Office 365," explained Ryan Sipes, managing director of product at Thunderbird, in a planning note last week for the development community. Thunderbird loses users each day to rich ecosystems that are both clients and services, such as Gmail and Office365 "These ecosystems have both hard vendor lock-ins (through interoperability issues with 3rd-party clients) and soft lock-ins (through convenience and integration between their clients and services). It is our goal to eventually have a similar offering so that a 100 percent open source, freedom-respecting alternative ecosystem is available for those who want it.
" Those losses aren't easy to measure since Mozilla does not publish user numbers for Thunderbird. But monthly active installations have dipped from 17,706,777 on December 27, 2020 to 16,174,806 on March 30, 2025. To bulk up and battle the behemoths, the Thunderbird team is developing a set of web services - some branded as "Thunderbird Pro," alongside "Thundermail" - each in various stages of maturity: Sipes says such services can be costly to run, so some folks will have to pay – a source of likely delight for Mozilla as it contemplates how it may have to replace the millions it receives from Google if the US government's Chrome-busting antitrust remedy is approved by the court.
"At the beginning, we plan to offer these services for free to consistent community contributors," said Sipes. "Other users will have to pay for access. Once we have a strong enough user base that the services appear to be sustainable, we will open up free tiers with limitations, such as less storage or the like – depending on the service.
" Users also have the option to host some of these services, such as Appointment and Send, themselves. Limits on free services like file sharing are necessary, Sipes observes, to prevent abuse. "Thunderbird is unique in the world," said Sipes.
"Our focus on open source, open standards, privacy and respect for our users is something that should be expressed in multiple forms. The absence of web services from us means that our users must make compromises that are often uncomfortable ones. This is how we correct that.
" ®.
