(Phys.org) -- Friday’s blog and news site revelations of an internal Mozilla email leading off with “Hello Mozillians” said there is to be a Mozilla Foundation announcement on Monday. The announcement is big. Mozilla is freezing further development of its popular and well-received email client, Thunderbird, which has over 20 million users. “We’ve been focusing efforts towards important web and mobile projects,” read the message from Jb Piacentino, Thunderbird Managing Director. The message noted that while Thunderbird is purely a desktop-only email client “We have come to the conclusion that continued innovation on Thunderbird is not the best use of our resources given our ambitious organizational goals.” The announcement on Monday is to carry details of Thunderbird’s proposed new “governance model.

“We’re not ‘stopping’ , but proposing we adapt the Thunderbird release and governance model in a way that allows both ongoing security and stability maintenance, as well as community-driven innovation and development for the product,“ said the heads-up message to its Mozillians.

Similarly, in a Friday blog posting from the Mozilla Foundation Chair Mitchell Baker, the Thunderbird freeze was reiterated that “Continued innovation in Thunderbird is not a priority for Mozilla’s product efforts.”

In some circles the news raised more questions than answers. A carefully spun message that Thunderbird was being killed off? Shot down except for maintenance and security fixes? A long goodbye? Time to hunt for another e-mail system? “Putting it in a hospice” was one site’s suggested take.

Mozilla will be pulling some in-house developers off the Thunderbird project but intends to continue handling bug fixes and security updates “This will mean an eventual shift in how we staff Thunderbird at Mozilla Corporation - we are still working out details, but some people will likely end up on other Mozilla projects,” said the Piacentino message. “Today the Thunderbird team is back in the main Mozilla product organization,” said Baker in her Friday blog.

The news may not have come as a big surprise, however, to Foundation insiders and those otherwise close to the situation. According to Geek.com, “We know that developers began moving off the Thunderbird team back in January. This has been coming for a while; we’re just learning about it now.”

Still, to others, this was unexpected and puzzling, considering Thunderbird, first released in 2004, had just got a new version in June. Users complimented Mozilla for its “rapid update cycle” for Thunderbird and Version 13 was allowing users to sign up for new custom e-mail addresses without having to leave the app. The Version 13 announcement was accompanied by the information that “In partnership with Gandi and Hover, you can now sign up for a personalized email address from within Thunderbird. Along with your new email address, Thunderbird will be automatically set up and ready to send and receive messages. We are working with additional suppliers to cover more areas of the world and to provide more options in the future.”

In Mozilla’s favor, reader reactions among those who use Thunderbird have been largely expressed as disappointment but continued support for the Foundation’s efforts to follow paths of growth. They largely say they do not like but understand the decision.

“As I lose more and more trust everyday in cloud computing and giving my information to companies for hosting on their servers, it was reassuring to have an e-mail system in place that gave me control over my e-mail,” said one comment to a site report. “Saddened to hear that Mozilla is making these changes, but understand it given today’s technological advances on the web.”

Also in Mozilla’s favor, e-mail market facts speak for themselves. Thunderbird has 24 million users but Gmail has 425 million users.

“Thunderbird provides an open-source, cross-platform email alternative for those of us who still use stand-alone email clients (and I am one). It’s trust-worthy, it’s under your control, and it’s built to reflect the mission,” wrote Baker in her Friday blog.

However, she said, “in parallel, we have seen the rising popularity of Web-based forms of communications representing email alternatives to a desktop solution. Given this, focusing on stability for Thunderbird and driving innovation through other offerings seems a natural choice.”

The Foundation is inviting those in the wider development community to continue work on Thunderbird if there is enough interest. The Thunderbird team is to propose a new release and governance model that would allow for ongoing maintenance in security and stability.

Final details of how this new “release and governance” model will work will be hammered out in the coming months. “We are going to open this plan for public discussion to individuals and organizations interested in maintaining and advancing Thunderbird in the future on Monday. We are looking for your feedback, comments and suggestions to refine and adapt the plan in the best possible way throughout the summer so we can share a final plan of action in early September 2012.”