Get Thunderbird Donate

Thunderbird 38 Released

57 responses

Thunderbird 38 is now released (actual initial version is 38.0.1 to maintain compatibility with equivalent Firefox releases). This release has some significant new features, as well as many, many bug fixes. Some of the new features include:

This is a significant milestone for the Thunderbird team, as it is the first release that has been fully managed by our volunteer team rather than by Mozilla staff.

Mozilla is still heavily involved with this release, as we still use Mozilla infrastructure for the build and release process. Thanks to the many Mozilla staff who helped out to fix issues!

Thanks to all of the volunteers who have contributed to make this release possible!

(Note that while general comments on Thunderbird 38 are welcome, please do not use the comment section of this blog as a place to make bug reports, or to request support for specific issues).

57 responses

Croydon wrote on

I expected that maildir would be the default. Why isn’t it that way?

Apart from that, good job!

kent wrote on

maildir is much improved over the previous version (where it basically did not work). I myself use maildir by default. But it is under-tested, and we would like more experience before both increasing its visibility, or enabling it by default. Not everyone thinks it should be the default.

R.M. wrote on

First of all, big thanks to you and all the volunteers involved with TB for this release.

My question is that based on your day-to-day use of the maildir format in TB, how comfortable you feel about it based on the performance, stability etc?. I use IMAP and would like to use maildir, but first interested in knowing what kind of issues etc to expect based on your use, before I turn it on. Thanks.

kent wrote on

I have no reservations on using maildir with IMAP, that is what I have been using for many months. The IMAP maildir is only used as an offline cache, so there is less risk of dataloss if there are unexpected problems. I have not experienced myself any maildir-related issues since the key patches were checked in a few months ago. Also note that for IMAP you should be able to select maildir in advanced configuration for a new account without setting the default. This does not work in POP3 for subtle reasons that cause the account to already commit to a message store type before you get to Advanced Configuration.

I have reservations about recommending it for POP3 unless you have a solid backup plan in place. But to put that in context, I would also have reservations about recommending auto compact in POP3 as well without a solid backup of the profile regularly.

Others on the Thunderbird team are more nervous about maildir than I am. Yet I along with a GSOC student wrote most of the fixes for maildir that are included in Thunderbird 38, so consider how that might bias my answers.

Ludovic wrote on

Because writting the migration from mbox to maildir didn’t happen.

Sparx wrote on

How do existing users of Gmail’s 2-factor authentication switch to the oAuth system? Can the application-specific passwords method of authenticating TB to Gmail be done away with now?

kent wrote on

In an existing GMail account, you can switch the “Authentication Method” from “Normal Password” to “Oauth2” (in both the IMAP and SMTP setup separately). Connection security should be SSL/TLS. If by “application-specific passwords method” you mean Google’s enabling of traditional IMAP passwords using their “less secure authentication” option, yes you can do away with that on an account using OAuth2 authentication.

LowEel wrote on

Do you think in the future some EWS capabilities will be included in the core program? The only one I can find is paid…. but EWS is now very common on free mail clients, i.e. the Android ones.


kent wrote on

The “only one you could find” at least for email is ExQuilla, which is written by me, so take my answers with the appropriate bias filter. Still I will try to answer in my role as the chair of the Thunderbird Council.

The short answer is that there is no expectation that EWS capabilities will be included in the core Thunderbird program.

The longer answer is more complicated. Several issues at play here:

1) The integration of Lightning that was done in Thunderbird 38 is a first attempt to control complexity, yet offer features to users in a reliable manner, by bundling certain functionality in addons that are shipped with Thunderbird. We expect to do more of this in the future. Since EWS can be implemented through an addon, regardless of the free/paid open/closed source issues involved, it would make sense to keep EWS as an addon.

2) You mentioned “paid” as your issue. A key challenge for the future of Thunderbird is figuring out how to raise income to fund our operations and code development, while maintaining our status as an open-source product. Somehow, somewhere, somebody must come up with actual money for that to happen. Asking users to pay to add a closed-source protocol like EWS to Thunderbird is one of the better ways to accomplish that. Personally I think that is a better way than selling either your personal information or access to your attention, as most “free” products do. So I don’t see any great interest in replacing paid additions with free additions in Thunderbird, be it EWS/ExQuilla or anything else. We would however like to make sure that the core Thunderbird development can receive some benefit from any income that others generate off of Thunderbird. Some organizations give back to the core product (ExQuilla being one example, Linagora being another) but most do not.

WildcatRay wrote on

I am curious. Does Thunderbird install Lightning on first run of a profile where the addon is not install and update it if it is already installed?

kent wrote on

What we understand will happen, and what we want to happen, is for Lightning to be installed for users that previously did not have it installed (with an opt-out option), and automatically updated to newer versions when there is a major update to Thunderbird. I hedge a little here because the code we are relying on to do this is not Thunderbird code, and there have been cases where we have encountered unexpected failures of Lightning to install.

ice upon fire wrote on

Massive thanks to all the volunteers involved into this release. Your work is very much appreciated. Keep up the good work.

Alex wrote on

I am trying to use the Yahoo chat plugin but it does not connect. There is no useful error message and the debug log does not help.

Suggestions appreciated.

Juan Sanmiguel ( wrote on

Thanks for the changes in chat for Twitter. Its great to have a character counter.

Barry wrote on

Do the recent developments toward convergence of desktops and phones – e.g., Ubuntu Phone, Universal Windows Platform, Windows Phone as Desktop – make it any more likely that Thunderbird will appear on a phone anytime soon?

kent wrote on

Trying to make Thunderbird run on a phone would essentially be writing a new program, and there are not current efforts trying to make that happen.

Giome wrote on

Thanks a lot 🙂

Robert wrote on

It seems that the new version ignores proxy (pac) settings, and tries to make a direct connection instead. In my case that doesn’t work due to firewalls. I did not find anything related in the release notes or in bugzilla.

It’s reproducible: if I reinstall TB31 then the proxy is used, everything works again. Upgrading to TB38 breaks things again.

Is this known or should I open a bug report?

kent wrote on

There were changes to the core way that proxies were handled, and this is causing a number of issues in Thunderbird. I am not aware of your specific issue though, so please file a bug.

Stefan Lehnert wrote on

Thank you so much for all your work and for continuing this great software! I hope, that soon there will be also the function for syncing with CardDAV-Servers without any Add-On. Keep up the good work!

Jonathan Morgan wrote on

If one wanted to test out maildir, is there a way to migrate existing mbox accounts, or would one just start over and re-download? I’d like to try it out. I’ve been looking forward to it for a while now.


Jonathan Morgan

kent wrote on

There is no migration program at the moment, so you need to start over with the account.

Poohs wrote on

Hi, as a “mature” user, and having unsuccessfully Googled for an answer, can you help please:

I use POP to access my e-mail on my desktop PC at home, but use IMAP on my notebook I carry around with me.

I have changed the settings on Thunderbird on both computers to use Oauth2, and the netbook has gone through the new authorisation process on Gmail, however the desktop seems to be exactly the same.

Plus, when I set my Google account settings to deny access to insecure applications, the desktop (POP) no longer works – I keep getting a “Password failed” message and telling me to log-on through web-access. Even when I do, this doesn’t make the desktop work.

Have I got the wrong end of the stick completely on POP/Oauth2/Google secure access ?


kent wrote on

OAuth2 access was added for SMTP and IMAP in Thunderbird 38, but not for POP3.

Poohs wrote on

Thanks for the reply.

Will OAuth2 access for POP be added to Thunderbird in the future ?

kent wrote on

There are no specific plans for this. Maybe you should file a bug requesting it.

Óvári wrote on

Thank you and the Thunderbird team for all your efforts and work in improving Thunderbird to be a full-featured desktop personal information management system.

It would be appreciated if you would advise the status of the following two items:

1. Do you know when Thunderbird will “Allow mbox (and maildir) folders larger than 4 GBytes”? (

2. You wrote on 31 June 2014 that “Thunderbird should be a full-featured desktop personal information management system, incorporating messaging, calendar, and contacts. We need to incorporate the calendaring component (Lightning) by default, and drastically improve contact management.” ( Thank you for incorporating the calendaring component (Lightning) by default. To enable migration from Microsoft Outlook 2010 before it will no longer be supported in 2020 to Mozilla Thunderbird, would you please advise the roadmap for the “drastically improved contact management”?

kent wrote on

1. For mbox, although there was substantial work done to remove the restriction to 4 GBytes, that was not finished in time for Thunderbird 38. For maildir these issues are not relevant s there is no 4 GByte restriction, but it has not been extensively tested with large folders.

2. The only substantial improvement in contact management for Thunderbird 38 was the ability to search multiple folders. For the future, the top priority in my mind is to support Carddav access to contacts. Really though contact management needs a complete redesign, and that has not made any progress, nor have critical issues to address been identified.

Óvári wrote on

Thank you for replying.

I hope that contact management will support the Carddav fields without the need to have contacts stored on a server, i.e. contacts stored on the local computer.

The contact management data stored locally could be copied and/or backed up to another computer.

Radiarajini wrote on

Great work,

Is there any option to integrate OCS Chat ? ( MS OCS/Lync communicator )

kent wrote on

I’m not aware of any option for OCS Chat, but I am not that up on the details of the chat implementation.

Nuno Guerreiro wrote on


I already installed the new Thunderbird version, on several Window PCs, but I don’t have the Calendar installed…
Is there any hidden option to enable or do I have to install the addon?!? Wasn’t supposed to be enable from the start?!?

kent wrote on

Whether Lighting is auto-installed depends I believe on the history of Lightning use on a profile. I’m not sure of the exact details.

Reiner wrote on

Hello Kent,
THANK you for all your Efforts for Thunderbird and the new version 38.01.
Unfortunately “Quicktext 9.11.5” does not work with Thunderbird 38.01.
I urgently need the functionality of Quicktext… Half the day I looked for alternatives but found nothing (I need several signatures incl. Graphics that I can place where the cursor is).
I found your statement in the Quicktext-forum.
Can you tell anything about the development of Quicktext?
Thank you very much for your reaction and with best wishes.

kent wrote on

I have contacted the developer of QuickText multiple times asking that he take the minimum steps needed to at least free the addon so that someone could try to fix it. After an initial response, I have not heard back, and he has not taken the needed steps. The addon is unlicensed (which means “all rights reserved”) so it is legally risky to attempt to fix it without some release from the author.

Reiner wrote on

Thank you.
What a pity!
Do you know any alternative, that does what Quicktext does??
You said, that you also use Quicktext… So how did you help yourself?
As for now I have gone back to Thunderbird 31.7 ;-(

kent wrote on

What I do is to find a previous message I have sent that has the standard text that I want, and cut and paste that into a new message. Painful.

The next step for me is to try and actually fix the addon. It’s an obscure bug whose cause is not obvious. Once I fix the bug, I can at least use it myself. It would be “fair use” to comment publicly on the fix, others could either modify themselves or someone could decide to take the risk and post the fixed version somewhere. Also maybe with the fix in hand I could persuade the author to take action.

Reiner wrote on

Please post the fix-lines, so I could fix the xpi-file by myself.
(I have already done this two or three times…. but I am not able to find the mistake/s by myself…)

Would you post the fix here or an the “official” add-on-Page of Mozilla?
Thank you for your time..
I appreciate this.

Reiner wrote on

Hi Kent,
I made some observations and found a workaround to work with Quicktext:

Within TB 38.01 you must not change anything in Quicktext 9.11.5 and save it – »save« is the problem. After new start of TB 38.01 Quicktext does not work correctly.

Correction respectively workaround:
– Install Thunderbird 31.7 (at Start cancel Actualization of addons)
– Install Quicktext 9.11.5 again (THIS ONE: – not the one on the HP of Emil Hesslow, seems to be buggy)
– Then make Changes you want in Quicktext and save.
– Then install Thunderbird 38.01 again – and everything is okay. Quicktext works as it should!
(For me this workaround is okay, as I do not often make changes in Quicktext.)

Nevertheless I hope you fine the mistake and publish it….

Tektro wrote on

For the time being Clippings add-on can be used as a replacement for basic functionality. In fact I do not need much more than Clippings has to offer. If only you could put shortcuts on new message window toolbar….

Here you can find Clippings add-on:

radu wrote on

How downgrade thunderbird, because after update to 38.0.1, all my exchange accounts is down ? I install/reinstall thunderbir, delete cache, etc, nothing work.

kent wrote on

There was a security improvement in the Mozilla 38 code, which Thunderbird uses, that replaced a 20 year old insecure Microsoft authentication protocol (NTLM version 1) with a version (NTLM version 2) that was introduced by Microsoft in Windows NT 4.0 15 years ago. So Mozilla is not exactly forcing people into spanking-new technology here.

Any update to security has the unfortunate side-effect of breaking people who use the older, insecure methods. It is not as simple as silently defaulting to the older method, as that is exactly what an attacker would want you to do. The correct thing to do is to update your server configuration so that it supports NTLM version 2.

Otherwise, you can tell Thunderbird to use the older protocol. I have a description for my addon users here: or you can check Generally this change is safe if you are using an encrypted connection (such as SSL) but not safe otherwise.

Charles wrote on

Thank you for all your work. For the last few weeks I have found Thunderbird very slow. I understand from the Thunderbird wiki that there are problems with multiple av programs. Do you have any plans to overcome this problem.

kent wrote on

There are no active projects to investigate various AVs and how they might affect Thunderbird performance.

Charles wrote on

That’s a real pity. Thanks for the reply.

Jim Witherspoon wrote on

My understanding is that the maildir files for the individual emails have no extension, and for this reason are not indexed by Windows Desktop Search. Can the .eml extension be added to these files so they will be indexed by WDS?

kent wrote on

There was a bug filed for that recently, and it is an interesting idea. It would not be hard to do.

Diego Garcia wrote on

We are having trouble on pcs that upgrade to Thunderbird 38 with our smtp server. For some unknown reason does not connect to our Exchange Server 2007. It works ok with older versions of Thunderbird.-

kent wrote on

This is a known issue, see for a workaround. The root cause is also known, and will hopefully be fixed in the next stability fix of Thunderbird 38.

Paul Donohue wrote on

After using Quicktext, the other work around solutions are slow and clunky. Can Thunderbird add a feature to do signatures?

Ineke Kuiper wrote on

A workaround to quicktext could be using AutoHotkey, a program that can be used to correct typo’s, but also for all kinds of other things.
I just checked, and when I enter


into the script, all the text between the parentheses is entered into an e-mail, including the returns.
So far, I have not found an option to add some code into it, like bold, but perhaps that would be possible too.

But this will work for replacing my signatures and other quicktexts I used.

I do find it a pity that quicktext is not working anymore, and it would be very nice if such a functionality would be included in Thunderbird itself.

MrArtist wrote on

Not sure I get this whole OAuth 2 for gmail, is it really working properly or still buggy?

I’ve had a reliable install of TB on Win 7 for years collecting emails from various sources and a gmail account. I have several gmail accounts but they all forward to one single one for collection but I do use several for outgoing all setup within TB.

I just tried the new OAuth authentication settings and it doesn’t seem to be working properly. For the incoming gmails I changed it to OAuth and that seemed to work fine when collecting but not when in Unified view. When I collect all in unified view I get an error saying the IMAP server does not support the selected authentication method. Unified view does not show the gmail emails, however when I look at the gmail folder view, I can see the gmail emails!

For outgoing, when I change the authentication to OAuth, I get similar error messages from gmail and cannot send anything from any of my gmail accounts.

This whole OAuth thing is just not working for me so will keep things as they are “Normal Password” and allowing so called “unsecure” applications from within gmail’s settings.

Any suggestions or advice?

kent wrote on

We’ve discovered that many users are using for their server URL, while the Thunderbird OAuth2 only works with (which is what you get from auto configuration). That will be fixed in the next version of Thunderbird in a week or two.

Andrew wrote on

Hello Kent; When we donate using the “Make a donation” on the About dialog box, do the funds go to Thunderbird specifically?

kent wrote on

No, funds sent to the donate link go to the Mozilla Foundation. Mozilla provides infrastructure to Thunderbird, so there is some legitimacy to that, but the main issue is that we do not currently have a legal method to accept and disburse funds for Thunderbird. That is a high priority after Thunderbird 38 is stable. Currently, the Thunderbird team has zero ability to accept or spend money, and zero funds available.

gms wrote on

Any plans to support the OAuth2 authentication for Microsoft email?

kent wrote on

What exactly do you mean by “Microsoft email”? There are no current plans to support OAuth2 beyond GMail, but that is mostly because we have not really thought about what other servers might need it.

Comments are closed.