Thunderbird Community Forum

Hi everyone, great to see the latest release of Thunderbird.

There was mention of an "experimental mode" that enables exchange active sync.

How/where can I access this since the previous plug-ins such as TBSync no longer work with the latest version.

Thanks.

Jeffrey

I'm struggling to understand where Thunderbird stores everything on a Windows computer so that I can use my incremental automated backup system to keep things backed up.

This support article :

[- Where Thunderbird stores your messages and other user data]

only mentions about the <user>\AppData\Roaming\Thunderbird\Profiles folder but there is also a <user>\AppData\Local\Thunderbird\Profiles folder that appears to be used and needed.

There is a ton of other conflicting 3rd party information out there so I'm hoping for a definitive answer here.

My question is : Can I backup just the '<user>\AppData\Roaming\Thunderbird\Profiles and <user>\AppData\Local\Thunderbird\Profiles and be assured that I will be fully able to recover my email client in the case of needing a complete reinstall ?

I have a Suddenlink.net email account that I can't seem to install. Suddenlink has been purchased by Optimum. I have all the requirements that Optimum has given, but it still won't load. my email address is dluenser@suddenlink.net. My password is correct because I can go to their site and get my emails. These are the requirements that they gave me. Again, it is a suddenlink account. Can you help? I've tried numerous times to work with Optimum techs, but they are not knowledgeable to what I should do.

Server Settings by Domain Use the following server settings to set up most third-party email clients or applications to send or receive Optimum email. IMAP (Inbound) Optimum incoming mail server: mail.optimum.net Suddenlink incoming mail server: imap.suddenlink.net Incoming mail port (SSL): 993 (Secure Connection. Recommended if your mail client supports) POP (Inbound) Optimum incoming mail server: mail.optimum.net Suddenlink incoming mail server: pop.suddenlink.net Incoming mail port (SSL): 995 (Secure Connection. Recommended if your mail client supports)

SMTP (Outbound) Optimum outgoing mail server: mail.optimum.net Suddenlink outgoing mail server: smtp.suddenlink.net Outgoing mail port (SSL): 465 (Secure Connection. Recommended if your mail client supports) • Check My SMTP server requires authentication Username and Password (if needed) User Name: Your full email address, including the @domain.net at the end (i.e. @optimum.net, @suddenlink.net) Password: The password for your particular email address • Outgoing server verification/authentication must be enabled and on. If your email client has the option or checkbox that says My outgoing server requires authentication this will need to be checked along with use same settings as my incoming mail server.

Hello, all,

My income has changed and I need to cancel my recurring donation. I used <redacted>@shaw.ca for my donation. My name is Dorothea Hoffman and I pay 1.75 Cdn monthly.

Thunderbird ver 140.0 (64-bit) on Windows 11.

Brand new, fresh installation of Thunderbird. - Added a GMail account. That worked. - I tried to add an account with my personal domain. I enter my name, the email account, and Thunderbird gets stuck in an unending loop looking up the configuration. - Other email clients have successfully looked up the config and did the setup without a problem. - The email account is handled via IONOS.com servers. - If you gave me a manual setup option I could handle it but there is none; TB goes straight into trying to handle it itself.

Any ideas?

TY, Frank

My user profile folder is 36GB (23GB compressed zip) consisting of 8 email accounts. My thunderbird version is 140.0esr (64-bit). It has been flawless and I back up the profile every week. All email accounts are setup as imap and original copies are in the cloud.

Setting aside bandwidth and storage limits, I am wondering whether there is an upper limit to the size of the profile folder?

Even if there is no upper limit, is there a better way to manage such a huge profile folder?

All my emails stopped receiving new emails yesterday when I had to go change my password on Google. Google has my on hold for 2 days for verification.

However, I have other non-Google emails that are not updating.

I also tried to create/add a new email account: EarthAlert1@outlook.com, and is stuck "Looking up configuration"

Hello, I apologise if this subject has already been discussed somewhere but I haven't been able to find anything that specifically answers my question.

I run Thunderbird on two desktop systems running Windows 7 Professional and a laptop running Windows 10 Home. The desktop systems are running Thunderbird 115.5.1 (32-bit) and the laptop 139.0.2 (64-bit).

I use a file synchronisation program to keep my data on all three systems in sync, which also acts as a backup. I also use it to back up my main desktop system to a portable hard drive.

I should like to know if it is possible to include Thunderbird data in the synchronisation process, specifically mail messages in various folders (e.g. Sent, Read - including subfolders, Deleted etc.), Address books and Calendar data. I have successfully transferred the message files and their .msf companions. The sync software detects and updates changed files and this seems to work smoothly but I haven't been able to do this with Calendar data or Address Books. As far as I can see this can only be done by exporting the data to iCalendar or csv files then importing to the other systems which is obviously not convenient for something that I am doing on a frequent, regular, basis.

A final problem I have encountered relates to message filters. I have not been able to find any way to copy these to the other systems. Copying msgFilterRules.dat doesn't work and I can't find any way to export the filter data.

I should be most grateful for any assistance you can offer.

Regards, M. J. Thompson.

Local folders were in default location on C: drive, 128GB SSD boot drive. Installed a 1TB SSD as D: drive. Want to use D: for local folders. When changed local drive to D: lost access to default Local Drive. Can't reconnect as location not visible in file explorer. Want to move local folder from C: to D:.

I have 3 e-mail accounts and the third one I added is the one I set as default. For some reason the first two show together in the unified folder, but the third is separate on it's own. How do I get all three in the unified folder?

Hi, Win 10 Pro new installation. Dell Optiplex MBR type Bios.

I had saved a recent profile to an external drive in its own name (i.e. not the profiles folder)

After the new Win 10 installation, I downloaded a new copy of Thunderbird.

I then copied the saved profile into the new Profiles folder, selected it in Choose user profile and started Thunderbird.

Thunderbird opened but not with the saved (8+ Gb) profile, just one new email account and asking for passwords to other email accounts I used before, and no folders.

I went back into the profiles folder and renamed all other profiles "OLDxxx999, but still the same one new email account when I opened Thunderbird.

I desperately need the saved email folders - I don't mind loading all the email accounts again, just need my court case history folders.

How can I force Thunderbird to use the saved profile, or can I identify and individually load in the saved local folders?

Thank you for any guidance towards a solution.

Does Thunderbird team consider adding option to log in to Mozilla Account on Thunderbird to store and transfer Thunderbird settings between user machines??

Or will this still need manual setup of each email account on every Thunderbird instance?

Hello,

I'm trying to add my secondary email account to thunderbird but I couldn't make it work. I've been using thunderbird for at least 15 years and this is first time I'm seeing anything like that. I think Account Hub is a new feature, I had to reinstall my PC and fresh Thunderbird installation came with it.

The account hub asks for my name and email address. I enter both and as soon as I click continue it says my username or password is incorrect. I don't get any prompt for password. It hangs and gets stuck here.

As an alternative I tried entering a made up email address (something like asd@ba.da) and then it gets into manual settings. I thought I could get it sorted that way but I was wrong. After I fill the form and click continue I get the blank error message. if I click advanced setup it gives me an error about cleanup property. I also get an error message sayign incoming server already exists, that's probably because I have another email account on the same server, but I'm not sure why this is an issue now. Can't I have multiple email accounts on the same mail server?

Probably this has something to with my mail server's autoconfig setup. However I believe user should be able to manually enter account config, incoming/outgoing server etc. At the moment I'm totally blocked and I can't add my second email account to thunderbird.

Thanks

New Laptop. Windows 11. Bitdefender protection. Installed Thunderbird and a first gmail account on new Laptop, all OK. Attempting to instal a second, different gmail account I get the following message from Google:

"400. That’s an error.  The server cannot process the request because it is malformed. It should not be retried. That’s all we know." 

No problem having installing the 2nd gmail account in my internet browser on new laptop after continued failures to instal in Thunderbird. NB I have both gmail accounts previously (and easily) installed and working in Thunderbird on PC, old laptop, phone. Issue does not make sense. Does anyone have a solution please.

I am using MacOS 10.13, Thunderbird 115.15.16ESR: my Hotmail worked until 15 May 2025 and then it would not download new emails. Screenshots are available if you want me to post them. I got an error message: "authentication failure while connecting to server outlook.office365.com". I updated Thunderbird to the latest for my OS: 115.18.0ESR. Still no new emails. I deleted my email account on Thunderbird and tried to reinstate it. Now I get an error message when trying to set up the account: "Unable to log in at server. Probably wrong configuration, username or password." I tested my password by logging into my Microsoft account with it on my browser. I can also login to my email using Firefox, but I want my Thunderbird email client to work again.

The configuration I am using is: I use my normal hotmail password in the password field. I also set up a new App Password with Microsoft and tried that without success. With the 115.18 update there is a new field: Your login. I just put my hotmail email address in here. incoming: outlook.office365.com, port 993, SSL/TLS, Oauth2 
outgoing: smtp.office365.com, port 587, STARTTLS, Oauth2 (I have also tried: smtp-mail.outlook.com)

I enabled 2-step authentication with Microsoft in my Microsoft account more than a year ago. Interestingly, I don't get a prompt on my iPhone Microsoft Authentication App when I select Done when trying to set up the hotmail account on Thunderbird.

Please help. I am desperate, and I have wasted a lot of time on this without success. Cheers

The PCs would not be used at the same time. (think winter/summer) POP3

I like the idea of reducing the places where the underlying data is potentially exposed.

If all files are synced after any local changes, will this work? Anyone see any potential issues?

Please let me know if any more information is required.

TIA!

years ago my Verizon.net email account was taken over by AOL. I can access that acct from the AOL web site. I would prefer adding it to my current Thunderbird account. I have tried various configurations, but none succeed. Suggestions appreciated.

I keep getting "Mozilla Thunderbird Email wants to access your Google Account", which I DENY. However, it keeps popping back up. How do actually get to DENY?

Hi, I am trying to use Filelink to send a large file. I selected WebDAV and am trying to log in there on Mozilla's Composition screen. Under Private URL it wants me to enter my username and password. I entered my email address and password but error message says account not properly configured, What am i supposed to do?