Forum der Gemeinschaft Thunderbird

In Thunderbird, the “attach” button stopped working when sending a message, although the “drag and drop” feature still works. Could you suggest what the problem might be?

Dear Thunderbird Support Team,

I am writing to report an issue with custom message tags in Thunderbird that started occurring around September 28, 2026 (likely following a recent update).

Issue Description: The problem applies to all folders (Inbox, Sent, custom subfolders, etc.) and is strictly isolated to user-created (custom) tags.

When I apply a custom tag to any email, the tag visually attaches to the message. However, as soon as I switch to another folder in the folder pane and then return to the original folder, the custom tag disappears completely.

Key Observations:

No Relation to Filters: This issue happens with regular emails in any folder, with no filters involved.

Custom Tags vs. Default Tags: This affects only custom tags created by the user. Default built-in tags (e.g., Important, Work, To Do) save correctly and persist after switching folders.

Timeline: All custom tags assigned before September 28, 2026, are still preserved correctly on older emails. The issue affects any new attempt to set a custom tag after this date.

Steps to Reproduce:

Select any email in any folder.

Apply a user-created (custom) tag to the email.

Observe that the tag is visually assigned.

Click on any other folder to switch views.

Return to the original folder — the applied custom tag is gone.

Could you please assist in resolving this issue or suggest a fix/workaround? Custom tags are essential for our daily email management.

Thank you for your help and support.

Best regards,

Ihor Hirnyi E-mail: ig@zrn.com.ua

Have been receiving alert notification that my hawaiiantel..net account is temporarily unavailable. My email messages to that account are not being received and I'm unable to move email messages to the inbox of that account. Have been receiving these alerts for the past 3-4 days. is there a way to resolve this problem?

Hi All,

I am on the latest release 156.0 on Windows 10. I have 3 email accounts, 2 gmail and 1 yahoo. The Yahoo account has been giving me problems since the last 2 weeks. Mind that yesterday I have a completely new Windows 10 installation so also TB installation is new.

I have renewed the Oath login, all messages were downloaded without a problem, but once in a while I get different notifications about server errors such as the ones below. There's also a third type of message error but haven't been able to get a screenshot of it.

Could someone please help me to solve this issue? I really don't understand why the problem is intermittent. Thanks in advance!

In the last couple days, I am not receiving messages in my email account inbox (att.net/yahoo). Messages are going directly to the local inbox folder. Windows 10.

When I search for new emails in the local folder, they are tagged with a gold diamond, and my option is to "Move to inbox again," which does move the messages back to the main inbox. But, "again" implies that the message arrived in the account folder, but got automatically passed to local folder. On or two occasions, I noticed an very fast dowloading to the inbox, which disappears immediately.

And, I get no response in my email account when hitting F5. F5 works for the local folder, and other accounts, and Shift-F5 (getting messages for all accounts) updates the others, but not my main email account.

The issue is not with att.net/yahoo. I have checked all my settings and server settings in Thunderbird, done the folder repairs several times, closed and reopened Thunderbird many times, deleted Inbox.MSF, etc., but nothing works. The issue seems to be specific to Thunderbird. Any ideas?

Thunderbird told me that I had to give the password of one of my email adresses again. So I added it but it did not work, so I changed my adress' password online and tried again, still nothing ; so I deleted my address from thunderbird and tried to ass it again but it still doesn't work

I checked all the previous infos, IMAPetc, everything is correct except in the end when I add the password (which is correct because I can access my email adress on the website with it), it does not work

I tried all the solutions I could find, like deactivating the "account hub" option, or getting rid of my antivirus, but nothing works...

Suddenly I can't attach images (or anything) to outgoing emails. I do this a lot and it worked fine all day yesterday, then stopped in the evening. When I click the Attach button, nothing happens. I've deleted 1000s of emails and compacted the folders, nada. My Thunderbird is up to date v153.4 on Win 10. Any ideas? Thanks, Andy.

Enclosed are jpg copies of the current sets of filters failures in my TB email program.

TB Error0 shows the 6 emails that have arrived and are placed in the INBOX. However, each of these has a corresponding filter set up to move them upon arrival to a separate subject email mailbox.

Note: If I highlight the INBOX and then go to Tools > Run Filters On Folder ... all of these INBOX email messages will be correctly filtered and moved to their respective email mailbox, BUT each of them is shown as having been "read" and unless you pay close attention, you may not know where these INBOX emails were sent.

I am also enclosing TB Error1 & 2 that show the last couple of days message filtering errors.

I can find nothing wrong with how each of these filters are set up, yet they seem to consistently fail to operate when new emails arrive.

Note one of them is for incoming emails from ... schiffsovereign.com. I have edited this filter repeatedly, even deleted it and re-input the information. Yet the filter never takes hold and does what it is designed to do. I am enclosing a jpg of that specific filter as TB Error3

I am looking for suggestions on how to fix this problem.

Thank you and best wishes,

/s/ James T Saint, CCIM COO

I am trying to send an S/MIME encrypted email from Thunderbird to:

jobcenter-chemnitz.netzwerkpartner@jobcenter-ge.de

The recipient certificate is provided by the official certificate directory of the German Federal Employment Agency (Bundesagentur für Arbeit).

I downloaded the recipient certificate and successfully imported it into Thunderbird under:

Settings → Privacy & Security → Certificates → Manage Certificates → People

The certificate is displayed correctly there. The email address contained in the certificate is:

jobcenter-chemnitz.netzwerkpartner@jobcenter-ge.de

The certificate is valid from July 29, 2026 to July 29, 2028 and includes E-mail Protection and Key Encipherment.

The required CA certificates are also installed:

BA-Class-1-Root-CA-4:PN BA-VPS-CA-11:PN

However, when I compose an encrypted email to this exact address, Thunderbird reports:

“You have selected to encrypt this message, but the application failed to find an encryption certificate for jobcenter-chemnitz.netzwerkpartner@jobcenter-ge.de.”

Under S/MIME → Recipient Certificates, Thunderbird also shows the certificate as “Not found”.

I have already tried:

deleting and re-importing the recipient certificate completely restarting Thunderbird after importing it manually typing the recipient address in lowercase without using autocomplete checking the complete CA certificate chain temporarily disabling OCSP

None of these changed the result.

My own personal S/MIME certificate works correctly. As a test, I can compose an encrypted email to my own email address without any certificate error. Therefore, the basic S/MIME configuration and my own certificate appear to be working.

When I reproduce the problem with the Thunderbird Error Console open, I get:

NS_ERROR_ILLEGAL_VALUE (0x80070057)

related to:

nsIMsgComposeSecure.beginCryptoEncapsulation

This seems similar to Mozilla Bug 2021265, where a manually imported recipient certificate is visible in Certificate Manager but is not found when composing an encrypted message.

Is this a known issue in Thunderbird 140 ESR, and is there a workaround for using this manually imported recipient certificate?

My email was rossmann@telkomsa.net My husband died on 25 May 2023 and telkom closed his account. I opened a gmail account. I am now wanting to open a few emails from 2022 regarding contracts but Thunderbird obviously only has my old email. Please could you assist me Kind regards, Chrissie Rossmann

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 have a filter setup to forward certain emails to another account. It has been working fine for years. Suddenly today I am getting an error message about not being able to contact the smtp server. If I manually forward the email to that same address it goes fine.