Thunderbird-mienskipsfoarum

Attached is a picture of what my account settings looks like. Thunderbird stopped syncing my emails from a gmail account. How do I get it to continue syncing my emails?

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.

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.

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.

1. 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. 1. 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. 1. 1. Server settings provided by the hosting provider

Incoming IMAP:

• Server: `mail.synergyappstudio.com`
• Port: `993`
• Connection security: SSL/TLS
• Authentication: Normal password
• Username: `connect@synergyappstudio.com`

Outgoing SMTP:

• Server: `mail.synergyappstudio.com`
• Port: `465`
• Connection security: SSL/TLS
• Authentication: Normal password
• Username: `connect@synergyappstudio.com`

1. 1. 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. 1. 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. 1. 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. 1. 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. 1. 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. 1. 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. 1. 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.

Every time I start Thunderbird it takes several minutes and sometimes doesn't start up. Once it does open up, emails do update new ones but if I go to account settings and select anything it hangs up. If I click on it, grays out and gets a message Thunderbird not responding. I have to open task manager to stop the program. Why aren't the emails on my email server get deleted/ moved updated when using Thunderbird? It seems like the only thing that happens only gets changed on the device I made changes to only. (computer, or phone or laptop)

As above, is there any EASY way to edit the Subject line on a received email. These days, most accounts are via email, and currently if I receive a bill for payment, I have to add an XNote or something similar, to note that I have paid, which means that you then have to open that email, to see it... Would be SO much easier, if I could just add a note to the subject line. Realise that you can (laboriously) go through the actual mail files and edit/create a script to do this, but before I go through the process, was thinking there must be an easier way??

Thanks,

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?

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.

All folders for email are working correctly except Business messages. The server shows 23% full, but the messages are not downloading. I have checked all the connections, and the incoming and outgoing servers are accessible. There seems to be one connection which is not set for Business messages, but I cannot find a solution

Ich versuche ein neues konto einzurichten. es scheitert an der Fehlermeldung authentifizierung nicht möglich

ich versuche mich mit einem mail konto anzumelden - wieder eine fehlermeldung obwohl mail adresse und passwort korrekt sind

Hi, After recent Thunderbird update Shift + F5 nor Get new messages for all accounts IMAP doesn't work. I've synchronisation on. When I start Thunderbird it gets messages fine.

Installed Thunderbird Setup 153.0.3 and npw when running t-bird get a prompt asking abut a 'thundermail" address. Please advise.. What is "thundermail" and why is it in my way? I am a regular donor to T-bird sent several, emails addressing the "thundermail" weirdness and thus far no reply. .

I've just recently (over the past 10 days) been notified about 3-4 times a day by Windows Defender which flagged "something" as Trojan:HTML/ScrInject.AW!MTB in "file" %temp%/newmsg.

That's where my copy of Tbird puts temp files. Closing it stops this behavior. Uninstalling and reinstalling w/out deleting my profile caused the same behavior, but uninstalling and cleaning out my profile files seems to have stopped this behavior.

I only have one extension, Compact Headers, and that doesn't seem to be the problem. Has anyone else experienced anything like this?

Jim

Hello,

My email provider is Thunderbird for my professional email address and I use Gmail everyday for receiving and sending my professional messages. However, Gmail will no longer support checking emails from third-party accounts through POP from my PC.

The option to 'Check emails from other accounts' will no longer be available in Gmail on computer. The solution that Google proposes is to set up automatic forwarding (web): To get new emails to appear automatically in my main Gmail inbox (like with POP fetching), set up automatic forwarding with your other email provider (Thunderbird). 

Can you help me with the different steps  in both Thunderbird and Gmail settings to make it work? Alternatively, is there another way to still have access to my professional emails through Gmail? Maybe through Gmail app for computer that uses IMAP instead?

For your information: My Thunderbird server settings shows:  Server type: POP Mail Server Server name: pop3.mycompany.com Username: xxx@mycompany.com (my professional email address) Port 995 Thunderbird has been updated and is currently running on version 153.0.3. My computer is running on Windows 10

Thanks so much!

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.