Mozilla Pull The Plug On Thunderbird Innovation

Mozilla have announced plans to cease in-house innovation of Thunderbird – the popular email client. As part of the decision, Mozilla will continue to provide future security and stability updates but will not innovate with new features:

On-going stability is the most important thing, and continued innovation in Thunderbird is not a priority for Mozilla’s product efforts”. It isn’t difficult to see why Mozilla (a non-profit org) have reached this conclusion:

1. Shrinking Email Client Market – Thunderbird has around 20 million active users but stats from 2011 show that this represented only a 1.21% share of the total market.

The desktop email client market is also shrinking rapidly – increasingly, users are consuming email via the web (and mobile apps), not on desktop clients like Thunderbird. [The exception is Outlook – due to its stranglehold on business email and appointments functionality]

For example, Gmail now has more than 425 million active users and Hotmail over 300 million.

2. Revenue Generation – Mozilla’s own browser, Firefox, has over 450 million active users and generates almost all of their income – as I reviewed here, it earns Mozilla an estimated $100 million per year from Google alone (for making Google the default search engine).

3. Firefox For Android – Last month I reviewed the new version of Firefox for Android which included significant improvements and has been very well received.

As the market for Android devices is growing so rapidly (1 million new Android devices are activated every day – 400 million in total) it clearly makes more sense for Mozilla to focus and invest heavily in this emerging market.

4. Firefox OS – Mozilla plan to launch a new fully open mobile operating system based on HTML5 – primarily aimed at low end smartphones.

Last week 7 leading mobile telecoms operators backed the plan and, because it is fully open and therefore cheap, the new OS may gain traction in emerging markets.

dodo thunderbird

Thunderbird or a Dodo?

What Does This Mean For Thunderbird Users?

Contrary to some reviews, Thunderbird is definitely not dead – but its wings have been clipped… The proposals for future releases are covered in more detail here.

Basically, the mainstream Thunderbird product will still be updated every 6 weeks (just as it is now) but just for security and stability – not for new features. Thunderbird ESR (Extended Support Release, 12 month lifecycle) will continue as before – the next release will be Nov 20th this year.

Mozilla have left the door slightly ajar to new features by suggesting that contributions from the developer community (outside of Mozilla) could be incorporated in future. However, they also note that “We’ve tried for years to build Thunderbird … where there is a growing, more active contributor base.  To date, we haven’t achieved this”.

Considering the small size of the Thunderbird market compared to its giant brother Firefox (and the decreasing market for email clients in general) it seems unlikely that this previous lack of success will change anytime soon.


It looks as if Thunderbird will no longer receive new features but will continue to be maintained for security and stability – it is already compatible with Windows 8 so it could have a future for some years to come.

It is not surprising that Mozilla are choosing to refocus their efforts on product areas that are growing – web browsers, Android and smartphones – rather than on a product which has a tiny share of a shrinking market.

Whilst it may be disappointing for users, I agree with Mozilla’s summary – “focusing on stability for Thunderbird and driving innovation through other offerings seems a natural choice”.