Thunderbird High CPU with status bar on

Thunderbird running 70-80% CPU with status bar showing. Once status bar is removed this drops. Have noticed some bug reports mentioned Linux but I'm on Windows 10 ESU (up… (ვრცლად)

Thunderbird running 70-80% CPU with status bar showing. Once status bar is removed this drops. Have noticed some bug reports mentioned Linux but I'm on Windows 10 ESU (up to date). Updated TB to 153.0.3esr but no improvement. Tried troubleshoot mode but no improvement. Also noticed that emails aren't getting moved to the deleted folder from inbox. Checked today and none had been moved for 3 days. I deleted some of the older ones from 'Deleted' and then it did update.

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Calendar today button not working after PC wake up

Little thing. None of the sections seemed appropriate. Win 11 153.0.3 (64-bit) In the left-hand panel of Calendar the top left icon of the actual calendar day/week/month… (ვრცლად)

Little thing. None of the sections seemed appropriate. Win 11 153.0.3 (64-bit) In the left-hand panel of Calendar the top left icon of the actual calendar day/week/month matrix is supposed to take you to today (though it's not obvious by the icon which changed a few versions back). When first coming to it after a restart (hibernation mostly in my case) it doesn't move the highlighted day. I have to click first on any other day, then click the icon for it to go to today.

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Sending emails with no subject line warnings

I am using Thunderbird Meadow. Is it possible to send emails without a subject, other than getting the warning dialogue box. It would be very useful. Thank you … (ვრცლად)

I am using Thunderbird Meadow.

Is it possible to send emails without a subject, other than getting the warning dialogue box.

It would be very useful.

Thank you

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IMAP/SMTP server connected, but receives and send fails

Thunderbird connects to my IMAP/SMTP server but neither receives nor sends mail I am having a problem with Thunderbird on Windows with a custom-domain email account ho… (ვრცლად)

    1. Thunderbird connects to my IMAP/SMTP server but neither receives nor sends mail

I am having a problem with Thunderbird on Windows with a custom-domain email account hosted by Advika Web.

      1. Account

Email address: `connect@synergyappstudio.com`

Mail hosting provider: Advika Web

The mailbox and password are confirmed to be valid because I can successfully log in to the provider's webmail using the same email address and password.

      1. Server settings provided by the hosting provider

Incoming IMAP:

Outgoing SMTP:

      1. What happens in Thunderbird

Thunderbird shows:

> Connected to mail.synergyappstudio.com

However, incoming messages are not downloaded and outgoing messages cannot be sent.

The SMTP error I received was:

> The connection to Outgoing server (SMTP) mail.synergyappstudio.com timed out.

      1. Connectivity tests

I tested the server from Windows PowerShell.

Port 993:

`Test-NetConnection mail.synergyappstudio.com -Port 993`

Result:

> RemoteAddress: 103.69.196.146 > RemotePort: 993 > TcpTestSucceeded: True

Port 465:

`Test-NetConnection mail.synergyappstudio.com -Port 465`

Result:

> RemoteAddress: 103.69.196.146 > RemotePort: 465 > TcpTestSucceeded: True

Therefore, both TCP ports are reachable from my computer.

      1. TLS tests

I also tested the actual TLS handshake rather than just TCP connectivity.

TLS 1.2 against IMAP 993 failed with:

> Unable to read data from the transport connection: An existing connection was forcibly closed by the remote host.

TLS 1.0 against IMAP 993 produced the same result:

> Unable to read data from the transport connection: An existing connection was forcibly closed by the remote host.

I also tested the TLS handshake against SMTP 465 and received the same "connection was forcibly closed by the remote host" result.

      1. Comparison with Outlook

There is an important comparison:

The same mailbox **successfully connects and authenticates in Classic Outlook** using the same server and credentials.

However, I am using Microsoft Office Home & Student, so Classic Outlook is not available to me as a practical permanent solution for this business email account.

Microsoft's **New Outlook** also fails to add the account and displays:

> Sign in failed. Please try again in a few minutes. You may need an app password.

The mailbox does not use Microsoft 365 authentication. It is a conventional hosting-provider IMAP/SMTP mailbox.

      1. Thunderbird troubleshooting already attempted

I have:

  • Confirmed the password works through webmail.
  • Confirmed the supplied IMAP/SMTP server names.
  • Confirmed ports 993 and 465 are reachable.
  • Confirmed SSL/TLS settings.
  • Used Normal Password authentication.
  • Used the full email address as the username.
  • Tried Thunderbird with the supplied IMAP/SMTP settings.
  • Reduced **Maximum number of server connections to cache** from the default 5 to 3 and then to 1. This did not resolve the problem.
  • Restarted Thunderbird after changing the connection-cache setting.
  • Tried Thunderbird's connection logging, but the generated log files remained 0 KB, so no useful log was produced.
      1. Additional observation

Thunderbird displays "Connected to mail.synergyappstudio.com", but the account does not actually synchronize incoming mail.

The provider's webmail works normally, and Classic Outlook works with the same mailbox.

      1. What I would like help determining

Could you please help determine whether this is:

1. A Thunderbird IMAP/SMTP compatibility issue with this particular mail server; 2. A TLS negotiation issue; 3. A Thunderbird configuration/profile issue; 4. A Windows/security-software interaction; or 5. Something specific to the mail server's IMAP/SMTP implementation?

In particular, I would like to understand why Thunderbird can establish the connection but cannot complete the IMAP/SMTP communication, while Classic Outlook works with the same server, ports and credentials.

I can provide Thunderbird version information, Troubleshooting Information, screenshots of the account configuration, or any additional diagnostic information you need.

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How do I change the standard number of copies in printing from Thunderbird?

Since some time my standard number of print copies in Thunderbird has changed from 1 into 2. I have to adapt this number each time I print. How can I change this back? … (ვრცლად)

Since some time my standard number of print copies in Thunderbird has changed from 1 into 2. I have to adapt this number each time I print. How can I change this back?

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sent email does not appear in sent email list

Bug report 15 Aug. 2026 The disappearing emails. It took me a while to find out what was going on. My friend said some of his Sent mail was nowhere to be found. After se… (ვრცლად)

Bug report 15 Aug. 2026

The disappearing emails.

It took me a while to find out what was going on. My friend said some of his Sent mail was nowhere to be found. After searching for it in a 'wrong' place it does not exist. Sending to the same recipient and again it just disappears. Simplifying the mail down to just address and the word "test", it still disappears. No combination of a Thunderbird search nor an Everything search finds anything. No return error message from this provider nor the recipients.

This address is for the local electricity board, other mails to other departments

go through correctly and are found in the Sent email directory.

A careful inspection of the contact information shows this is the only department

without a "Shown Name" it only has an email address filled in.

Entering a Name for this contact solves the problem, it now shows up in the Sent

folder and is easily searchable.

I hope this explanation helps some one else with a 'Houdini' email.

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153 esr Changes to windows buttons

Hi. Just had a not requested update to 153 esr, which in itself is generally fine, with a small exception. The windows min, max and close buttons all come up with a code.… (ვრცლად)

Hi.

Just had a not requested update to 153 esr, which in itself is generally fine, with a small exception.

The windows min, max and close buttons all come up with a code.

Probably just some weird setup I have but any ideas will be welcome.

I use userChrome.css to give a background colour, so maybe the ID of each has changes for any css

  1. titlebar-min{height:1.66em; background:#00b !important}
  2. titlebar-max{height:1.66em; background:#090 !important}
  3. titlebar-close{height:1.66em; background:#d00 !important}

but I don't see how that would effect the actual bare icon

Thank you

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The last major update broke tags in my setup.

I usually browse my emails using saved search folders. Messages in these search folders are losing their tags. I tag the messages, and when I browse them later, the tags … (ვრცლად)

I usually browse my emails using saved search folders. Messages in these search folders are losing their tags. I tag the messages, and when I browse them later, the tags are gone. The same happens in regular folders and subfolders. If I browse the regular folders and tag messages while visualizing these folders, the same happens again. Any guesses?

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Messages won't download

My e-mail stopped downloading. It was working fine, I changed nothing, no error message. It accepts my password, cycles through it's process, then quits without downloadi… (ვრცლად)

My e-mail stopped downloading. It was working fine, I changed nothing, no error message. It accepts my password, cycles through it's process, then quits without downloading anything. Sending still seems to work.

We did relocate from home to my folks' in-between, but I've never had issues at their place before, and otherwise my connection to their wireless works fine.

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The "Get Messages" button stopped working in Thunderbird

I'm on TBird 153.0.2esr after a recent update. On previous versions the "Get Messages" button in the top left side of the menu's was working fine. When the button was s… (ვრცლად)

I'm on TBird 153.0.2esr after a recent update. On previous versions the "Get Messages" button in the top left side of the menu's was working fine. When the button was selected, an update was displayed in the bottom left frame of the window. The update would say something like "Connecting to ..." and the message would be downloaded from the server. Great...

If there were no messages on the server, the update would display "There are no messages on the server". With this current version, I don't see any messages in the lower left frame of the window.

This is a convenient feature of the app, as I like to check the server for messages prior to shutting down. It's also convenient for getting messages with a security code without having to wait for the next scheduled message download. Now I can only assume there are no incoming messages when I push the button and don't see anything in my Inbox.

Dear Mozilla Development Team, Please reinstate this feature for upcoming versions of Thunderbird. Oh, BTW, this is a great app that I use daily for email. I use the calendar as a log book for my daily activities as well as an appointment scheduler. Thanks for your attention.

P.S. I see a new version is available (153.0.3esr) today (8/14/26), so I'll update and see if the same issue occurs.

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thunderbird always asks for passwords on startup

Ever since last 2 windows updates, thunderbird always asks for passwords and authorization for google calendar...this happens when you restart the computer and when you l… (ვრცლად)

Ever since last 2 windows updates, thunderbird always asks for passwords and authorization for google calendar...this happens when you restart the computer and when you log out of thunderbird and log back in....this never happened before I uninstalled thunderbird and reinstalled it and it keeps happening is there a fix?

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Unified folder listing shows one account but not another?

Hi, I have two accounts in my Thunderbird. They are Gmail (regular gmail account) and CFCC (an institutional account). The CFCC shows up in my Unified Folder list but … (ვრცლად)

Hi, I have two accounts in my Thunderbird. They are Gmail (regular gmail account) and CFCC (an institutional account). The CFCC shows up in my Unified Folder list but the Gmail does not. Is that normal? The main Inbox is showing all incoming emails from both accounts so no performance issues, just wondering how to get rid of the CFCC (if that's possible) to eliminate clutter. Thank you. GES

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thunderbird has stopped receiving emails from century link

thunderbird has stopped receiving e-mails from century link. Configurations worked for two years as pop3, now won't connect. Tried imap configuration, same issue. Chan… (ვრცლად)

thunderbird has stopped receiving e-mails from century link. Configurations worked for two years as pop3, now won't connect. Tried imap configuration, same issue. Changed password (CenturyLink has problems with some password characters), still will not connect. AI (co pilot) tells me it is an issue since CenturyLink made changes, but they blame the email app (tried with Samsung app, thunderbird, outlook, none will connect. Connection thru CenturyLink web page works fine.

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Passwordeingabe nach jedem Update neu erforderlich

Seit ein paar Monaten verlangt Thunderbird nach jedem Update die erneute Eingabe der Passwörter für die Verbindung zum emailprovider und zum google Kalender. Das ist ext… (ვრცლად)

Seit ein paar Monaten verlangt Thunderbird nach jedem Update die erneute Eingabe der Passwörter für die Verbindung zum emailprovider und zum google Kalender. Das ist extrem nervig und war in all den Jahren davor nicht erforderlich. Warum ist das so bzw. wie kann ich die Neueingabe nach jedem Update vermeiden?

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Bitte um kostenfreie Emailadresse von Thunderbird, wo meine Yahoo Emails geladen wurden. Vielen Dank

Guten Tag, ich habe meine Yahoo Emails alle erfolgreich auf Thunderbird übertragen. Danke dafür! Nun möchte ich bitte thunderbird als Standard Email und NICHT mehr yahoo.… (ვრცლად)

Guten Tag, ich habe meine Yahoo Emails alle erfolgreich auf Thunderbird übertragen. Danke dafür! Nun möchte ich bitte thunderbird als Standard Email und NICHT mehr yahoo. Wie lautet meine thunderbird Email für Visitenkarten usw.? Yahoo soll bleiben aber nicht mehr als erstes Email Programm. Ich möchte auch yahoo emails löschen, die dann aber bei Thinderbird erhalten bleiben! Wie stelle ich das an? Im Moment sind beie email Programme ein zu eins verknüpft. Ich möchte bitte nur noch mit Thunderbird primär arbeiten und benötige dazu eine Email Adresse. Kostenfrei. Also OHNE Kosten! Das ganze auch aucf dem iohone. Mein Mac Book hat es schon Ganz ganz vielen Dank

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