Thunderbird Community Forum

We use Thunderbird because of its flexibility across multiple OS and interfaces. We have only one PC using Windows, and that is a Microsoft surface running Windows 11. On that machine, emails are, from time to time, delayed, sometimes by 12 hours or more.

The emails come through normally on Android and Linux machines, and we had no difficulty on the Surface until we upgraded it from Win10 to Win10. The emails can also readily be accessed using a web interface to the provider's Apache server. Meanwhile, asking Thunderbird to get emails consistently reports "No new emails".

This is a very intermittent problem, with no discernable pattern to when it happens, or how long the messages get delayed.

Can anyone give me some pointers on where to start troubleshooting this?

On Saturday morning 27 June 2026 I tried to login my Orcon email account via Thunderbird (which I have been using for a long time). But my login didn't work, I got a message saying "login to POP3.orcon.net.nz with username habitation failed." On 30th June 2026 I reported the problem to Orcon.

Orcon gave me the following settings for Thunderbird. I have done that and even made a new account: Incoming Server Type: IMAP Mail Server: imap.orcon.net.nz Port: 143 SSL: Off Authentication: On (username and password required)

Outgoing SMTP Server: Mail Server: smtp.orcon.net.nz Port: 25 SSL: Off Authentication: Off

Since then I have spent many hours and going around in circles with Orcon's Technical Support to resolve this, but no luck. They blame Thunderbird. I used Thunderbird Troubleshoot Mode. The message that comes up reads: login to server mail orcon.net.nz with username habitation failed. Please can you check that your server settings above are correct? And if there is a bug? Irma

For about a week now I have been unable to send emails. Receiving them is fine. 1 had just said yes to the latest update. When I try to send I get this message - Sending of the message failed. An error occurred while sending mail. The mail server responded: Service unavailable; Client host [125.214.85.178] blocked using b.barracudacentral.org; http://www.barracudanetworks.com/reputation/?pr=1&ip=125.214.85.178. Please check the message recipient "reply-fe9515767360017975-18_HTML-75443594-7238404-12125@emails.avg.com" and try again.

I am 71, not technologically minded but am rather frustrated by this.

I hope you can help me out.

Thank you

Rita

My recollection is that prior to a recent automatic update to Thunderbird 140.12.1esr (64-bit) when I had a message composition window open, there were "SEND" button and possibly a "SEND LATER" button (to the left of the addressee and cc addresses in addition to the keyboard shortcuts (CTRL ENTER and CTRL SHIFT ENTER).

Following the update, there is no longer anything to the left of the addressee information. I have checked the toolbar menus, and there do not appear to be any button options. I can still send messages, but the lack of the buttons is a hindrance.

Hi

I have set up Thunderbird with a Zimbra mail serveur (Zimbra serveur 10.1.10_GA_4785) using the EWS new feature of Thunderbird.

I can setup the EWS account. The test of the secured connection to the server is returned valid. But in the mailbox, the list of folder is empty, and I see no email. Interestingly, I can successfully send email from this thunderbird using the exchange server as sending server.

To resume, no emails are received, but sending emails works.

So, I check the request to the exchange server when starting a synchronization : Here the result : Request : <soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/" xmlns:t="http://schemas.microsoft.com/exchange/services/2006/types"><soap:Header><t:RequestServerVersion Version="Exchange2010_SP2"/></soap:Header><soap:Body><GetFolder xmlns="http://schemas.microsoft.com/exchange/services/2006/messages"><FolderShape><t:BaseShape>IdOnly</t:BaseShape></FolderShape><FolderIds><t:DistinguishedFolderId Id="msgfolderroot"/><t:DistinguishedFolderId Id="inbox"/><t:DistinguishedFolderId Id="deleteditems"/><t:DistinguishedFolderId Id="drafts"/><t:DistinguishedFolderId Id="outbox"/><t:DistinguishedFolderId Id="sentitems"/><t:DistinguishedFolderId Id="junkemail"/><t:DistinguishedFolderId Id="archive"/></FolderIds></GetFolder></soap:Body></soap:Envelope>

Response <soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/"><soap:Header><ns2:ServerVersionInfo xmlns:ns2="http://schemas.microsoft.com/exchange/services/2006/types" xmlns="http://schemas.microsoft.com/exchange/services/2006/messages" MajorVersion="14" MinorVersion="3" MajorBuildNumber="158" MinorBuildNumber="11" Version="Exchange2010_SP2"/></soap:Header><soap:Body><GetFolderResponse xmlns:ns2="http://schemas.microsoft.com/exchange/services/2006/types" xmlns="http://schemas.microsoft.com/exchange/services/2006/messages"><ResponseMessages><GetFolderResponseMessage ResponseClass="Error"><MessageText>Cannot invoke "com.microsoft.schemas.exchange.services._2006.types.DistinguishedFolderIdNameType.value()" because the return value of "com.microsoft.schemas.exchange.services._2006.types.DistinguishedFolderIdType.getId()" is null</MessageText></GetFolderResponseMessage></ResponseMessages></GetFolderResponse></soap:Body></soap:Envelope>

The parameters ( domain replaced by *** for privacy) mail.ews.server_versions : {"https://zimbra.*******.com/ews/Exchange.asmx":"Exchange2010_SP2"} mail.outgoingserver.ews1.auth_method : 3 mail.outgoingserver.ews1.ews_url : https://zimbra.*******.com/ews/Exchange.asmx mail.outgoingserver.ews1.key : ews1 mail.root.ews-rel : [ProfD]Mail mail.server.server4.ews_url : https://zimbra.******.com/ews/Exchange.asmx mail.smtpserver.ews1.type : ews

Anyone successfully used the new EWS feature with Zimbra server ?

PS : I confirm the EWS connection with the Zimbra serveur by successfully using EWS on Outlook for android.

Hello,

Everything working just fine last night. Wake up and Thunderbird will not retrieve emails.

Remembered this old message I got so I went through and deleted my second email address, didn't help.

https://support.mozilla.org/en-US/kb/thunderbird-and-yahoo

Checked all settings compared to Yahoo, still won't download messages. I can even send a message with my current settings no problem, and it does login, just won't retrieve emails. Gives me a connection timeout.

Anyone have any ideas?

I cant receive emails only send them. I receive an error message when starting Thunderbird "the current operation on inbox <my email address> did not succeed"

> I have 6 email accounts I manage in my Thunderbird. > Normally I do not delay sending emails, so I have not had a reason to use the Unsent Messages Folder. > I recently installed Thunderbird's Mail Merge Add-On to send mass individual emails to classmates for a school reunion. Doing it this way will allow me to track individual bad emails. I have a total of 3621 emails. > I created a new Gmail Account for this purpose. > There is a concern to not send too many emails out at once to avoid getting flagged and suspended by Gmail as a Spam Account. (Limits of 50 to 500 per 24 hr period have been suggested to avoid this), so scheduling bursts of emails over a period of time is necessary. > The Mail Merge Add-On has 3 output choices, Save as Drafts, Send Later, Send Now. (The instructions warn against using Send Now) > I tried the Save as Drafts function and it performed as promised, creating 3621 individual customized emails in my Account's Draft folder. This, however, makes it so you have to send each email individually. > When I tried the Send Later function, it appeared to work, but a Local Folders > Unsent Messages folder never appeared. I searched all my other email accounts and finally found it in the one Old Defunct email account list that I never use anymore. It does appear to have created all 3621 emails. > I tried to Drag & Drop it into the Local Folders stack, but received an error message that a folder of that name already exists there, even though it does not appear in the list of folders. > I tried repairing folders, compressing folders and was not able to move it or even create a new one of that name and copy the contents. > I would like advice on how to proceed to complete moving/copying the Unsent Messages folder to its proper location in the Local Folders stack. Thank you! greg

Login to server smtp-mail.outlook.com with username XXXXXX@outlook.com failed.

I am having this error I have tried logging back in, can download mail but not send any. Any ideas? Thank you

Thunderbird 152.0.1 Mac

After sending on one of 4 accounts in Thunderbird (Sky Mail), the "Filter Complete" modal will not shut down.

Cancel will override.

When email downloads from my internet server to thunderbird how do I indicate that the message is to be deleted from the server. ie I dont want the message to be in two places . At the moment after reading the email and saving it to a folder I have to log into my internet provider and delete the email.

Yesterday I downloaded 90 emails from my mail server. Only 5 of them were filtered correctly.

Upon reviewing the remaining 85 emails, I observed that many of them "should" have been filtered. So I opened up the Tools - Message Filters and applied the filtering to the INBOX file.

Almost immediately, all 85 emails disappeared. They were not in the Trash folder, nor were they visible in any other folder or mail box that I could see.

It was recommended to apply the "repair" to the INBOX which I tried; However, all that happened was 318 older emails that I have processed a few days before reappeared in the INBOX. Which interestingly would not sort by the date indicated for the email; they would only sort by subject and sender.

It was further recommended to close TB, and delete the INBOX.msf file. Which I did do. In addition, I also restored the INBOX to the previous days file using my daily backup files. That file shows 101,076 kb of info contained in it.

I reopened TB to find once again nothing in the INBOX, and when I tried to re-run the get msgs aspect, the result was the system telling me there were no email messages to collect.

Yet I know the same 90 emails are still sitting in the mail server system.

Why did this happen?

Where did the 85 emails in the INBOX go to?

Why isn't the set of 2200++ email filters not automatically filtering all emails once they are collected, and distributing them to the appropriate email file folder / mail box?

What recommendations are available to help me resolve this situation and prevent it from happening again?

Also, I have a txt and html file of the 8 Jul 2026 filter report. Why can't I upload said files along with this set of information? Why are attachments only restricted to image files?

Thank

My computer was hacked a month ago, well... I got phished when I was sent an email that looked like it came from a client, it was a bit premature to receive a file from her but... it was very late, I wasn't at my best, and there it is. I always thought I was savvy. So. I did catch it in time to save my Google account and they didn't succeed in getting at any money, did lose my longtime alt-email address. My computer tech was able to restore most of Thunderbird, except for all my client information (18 years' worth), which I theorize is because the bad file was filtered into my client folders so those 2 main/many subs were deleted (or it could be because those client folders and a couple others missing were near the bottom of the folder tree and the tech guy's backup program failed at that point, he did try again but no luck). Fortunately I still keep a paper schedule so I was able to figure out who to talk to, and the autofill feature of TB was able to give me most of the emails I needed. [I have since learned about and have moved my Profile into my Documents in a separate folder so that my cloud backup picks it up every day (idrive). I really think it should be a LOT LOT easier to find and utilize the information on the Profile because EVERYONE should be backing that up every day, and the best way is to automate it. [My tech guy (re)installed Windows 11 Pro, I had Home by preference, have a tutorial from a trusted source about going back to Home without losing anything, because I do not need or want the architecture of Pro. But not doing that until I get my computer stabilized.]

All that said, to get to the point. When I collect email in TB (I have a gmail account using POP into TB as I do not like syncing and use TB to track), I usually have more than 200 emails at a time before I d/l into TB. Several times each d/l session, I get the following error message (header is cut off, it just contained my email address):

<<Unable to write the email to the mailbox. Make sure the file system allows you write privileges, and you have enough disk space to copy the mailbox.>>

I have write privileges and there is plenty of disk space. I press OK and the d/l continues for a few more emails and then stops. I then press F5 again to start d/l again. Several times a session. There is no information about which folder isn't there or what is missing or causing the error.

It appears to me that the filters are telling TB to filter into a now-nonexistent folder. I did reconstruct my client folders, but plenty of room for error there I imagine (I use QuickFolders and that actually told me which of the visible tabs no longer existed). My old laptop died in the process of all this so no longer have another version of TB as a guide. I have 367 filters (been using TB since Eudora went away), but they are only searchable by name of filter, not by possibly now-missing folders.

1. I assume that this error only means the email isn't filtered, it doesn't mean it has been deleted or anything. yes? Or am I totally wrong about the meaning of this error message, and if so, please help! 2. What can I do to fix the error? With 367 filters, it would be nice if there were some way I could figure out a way to know which filter is failing, if indeed this is a filter problem?

Thank you for any input about this. I have tried and tried to figure this out.

All best wishes, --Victoria

Thunderbird Send message Error Sending of the message failed An error occurred while sending mail. The mail server responded: Must issue a STARTTLS command first. For more info, go to https://support.google.com/a/answer/3221692 and review RFC 3207 specifications. ffacd0b85a97d-47aa0f2186bsm33992962f8f.36 -gsmtp. Please verify that your email address is correct in your account settings and try again.

Note: I could not find the suggested specifications as indicated in the error message!

I did not change anything, the sending error occurred suddenly , all my settings IMAP Mail Server Port 993 SSL/TLS OAuth2 and SMTP Port 465 are still set to default. I changed also the SMTP to an new shown default 587 but non of this settings resolved the problem

I am using Thunderbird for my emails since gmail will no longer support my business emails. I was able to access my sent emails up until April and now I am no longer seeing sent emails show up in the sent folder. Please provide easy to follow steps for this. I need to be able to access my sent emails.

None of my sent emails are accessible. When I go to the sent folder after sending an email, the emails are not there. Same with deleted emails. When I go to that folder, they are not there. Why is Thunderbird email so overly complicated? I think I need a better email provider. I am only using it because gmail will no longer support 3rd party emails (for my business.)

Good afternoon,

We are experiencing the following issue.

I work as a Technical Support Engineer at a large company in Russia. All of our branches use Thunderbird as their email client.

Approximately three weeks ago, we started receiving reports from users that their email was no longer working.

After investigating the issue and trying to identify the root cause, we have not been able to find a permanent solution. We have already tried the following:

1. Completely clearing the cache, rebuilding the mailbox while preserving emails, and allowing Thunderbird to re-download all messages. 2. Changing the `mail.server.default.mime_parts_on_demand` and `mail.imap.mime_parts_on_demand` configuration settings to `false`, clearing the Trash folder, and restarting Thunderbird. (This only provided a temporary fix.) 3. Reinstalling Thunderbird and creating a fresh client installation. 4. Using the **Repair Folder** and **Compact Folder** options for every mailbox folder. 5. Several other troubleshooting methods found online, none of which resolved the issue.

According to multiple users from different departments who are not connected to one another, they all describe the same behavior:

Thunderbird stops working for about half a day. Then it starts working normally for approximately 15–30 minutes, after which it stops working again for another several hours. During these periods, no new emails are downloaded, regardless of the size or content of the messages.

When checking the mailbox size in Exchange, it reports:

• 3.56 GB used. The quota is unlimited.

However, on the local computer, the Thunderbird profile folder (`Thunderbird > Profiles`) occupies nearly 9 GB. If we calculate the size of all mailbox folders within Thunderbird itself, the total is approximately 6 GB.

Does anyone have any suggestions on what else we can try?

Has anyone experienced a similar issue or found a solution?

At this point, our employees are unable to work effectively because email is a critical part of their daily workflow, and we have been unable to identify a permanent fix.