Thunderbird 커뮤니티 포럼

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.

I updated t the latest version of Thunderbird but since then none of my email addresses were changed with the update. Tried all the advice on line but still can't retrieve my saved email addresses from the inbox and sent box

We're planning to switch from Outlook to Thunderbird, but we have a hard time in harmonizing font sizes on text and signature. One of the issues is that fonts can be set to textual values tiny, small, medium, etc. w/o knowing what it corresponds to in pt. But lets explain what we tried so far: - Under Settings/ General / Language&Fonts, we defined Calibri 12 as default, what we repeated under Advanced for 'Latin' & 'Other Writing Fonts' - Under Settings / Composition, we defined Calibri / Medium for the HTML Style - The HTML-signature is defined using the Calibri 12 font But when creating a new message w/ these settings, the result is terrible as you can see in the example: disregard the fonts' color, just look at the font sizes.

Is there any simple solution?

After returning from a 6 day vacation, my wife attempted to download email from her Yahoo email account. There are nearly 200 messages that have piled up but they aren't moving. I've uninstalled and re-installed TB. I've uninstalled and reinstalled the app password in Yahoo. There is no problem with accessing the email via any web browser. I spent 49 minutes on a tech support call with Yahoo and they have said the problem is with TB because they repeated the same steps I have. I checked firewall settings and the only antivirus program on the computer is Malware Bytes and it's not running in the background. The version of TB is the most recent as of yesterday. I don't see any sketchy looking emails in the web version of Yahoo Mail when it's opened. It's set up as a POP3 account and has been since Cox Internet gave their email over to Yahoo. I'd appreciate any assistance in resolving this because it's currently above my pay grade and tech support at Yahoo.

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)

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?

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.

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

Thunderbird for NixOS nixos - 1.0

I could not figure out how to provide a log at all. If there is a way, please let me know and I will provide one.

Whenever I try to log in with gmail, I get stuck on this dead end:

1. Set up gmail server config (because my email ends in @vcu.edu, however I have tested this with a proper @gmail.com email and observed the exact same behavior)
2. Get propted to login with google, which works
3. Get to the "Mozilla Thunderbird Email wants access to your Google Account" page, select all and hit continue
4. get redirected to `http://localhost:35141/?state=<string of chars>&iss=https://accounts.google.com&code=<another string of chars>&scope=https://mail.google.com/%20https://www.googleapis.com/auth/carddav%20https://www.googleapis.com/auth/calendar` This page does not load, I just get a "unable to connect" error
5. get a notification stating "Authentication failure while connecting to server `imap.gmail.com`
6. get ANOTHER prompt to log in with google, exact same thing happens

please note that the port is random and is different every single time. also, google does not register that I have allowed Thunderbird access to my account, and it prompts me again every single time. Open ports: ``` sudo ss -lntup [sudo] password for jane: Netid State Recv-Q Send-Q Local Address:Port Peer Address:Port Process udp UNCONN 0 0 192.168.122.1:53 0.0.0.0:* users:(("dnsmasq",pid=2224,fd=5)) udp UNCONN 0 0 0.0.0.0%virbr0:67 0.0.0.0:* users:(("dnsmasq",pid=2224,fd=3)) udp UNCONN 0 0 0.0.0.0:33289 0.0.0.0:* users:(("librewolf",pid=185950,fd=164)) udp UNCONN 0 0 0.0.0.0:35410 0.0.0.0:* users:(("librewolf",pid=185950,fd=161)) udp UNCONN 0 0 0.0.0.0:52393 0.0.0.0:* users:(("librewolf",pid=185950,fd=218)) udp UNCONN 0 0 0.0.0.0:21027 0.0.0.0:* users:(("syncthing",pid=1850,fd=19)) udp UNCONN 0 0 0.0.0.0:54112 0.0.0.0:* users:(("syncthing",pid=1850,fd=33)) udp UNCONN 0 0 0.0.0.0:5353 0.0.0.0:* users:(("avahi-daemon",pid=1148,fd=11)) udp UNCONN 0 0 0.0.0.0:41088 0.0.0.0:* users:(("librewolf",pid=185950,fd=169)) udp UNCONN 0 0 0.0.0.0:59247 0.0.0.0:* users:(("librewolf",pid=185950,fd=132)) udp UNCONN 0 0 [::]:44815 [::]:* users:(("syncthing",pid=1850,fd=29)) udp UNCONN 0 0 *:1716 *:* users:((".kdeconnectd-wr",pid=185637,fd=15)) udp UNCONN 0 0 [::]:21027 [::]:* users:(("syncthing",pid=1850,fd=34)) udp UNCONN 0 0 [::]:5353 [::]:* users:(("avahi-daemon",pid=1148,fd=12)) udp UNCONN 0 0 *:22000 *:* users:(("syncthing",pid=1850,fd=15)) tcp LISTEN 0 4096 127.0.0.1:8384 0.0.0.0:* users:(("syncthing",pid=1850,fd=17)) tcp LISTEN 0 32 192.168.122.1:53 0.0.0.0:* users:(("dnsmasq",pid=2224,fd=6)) tcp LISTEN 0 4096 127.0.0.1:8080 0.0.0.0:* users:(("systemd",pid=1,fd=847)) tcp LISTEN 0 4096 127.0.0.1:631 0.0.0.0:* users:(("cupsd",pid=1814,fd=4),("systemd",pid=1,fd=997)) tcp LISTEN 0 50 *:1716 *:* users:((".kdeconnectd-wr",pid=185637,fd=16)) tcp LISTEN 0 4096 [::1]:631 [::]:* users:(("cupsd",pid=1814,fd=8)) tcp LISTEN 0 4096 *:22000 *:* users:(("syncthing",pid=1850,fd=21)) ```

I believe this is all the information i can provide. Firewall was disabled for testing. I cannot log into either my school or personal gmail accounts.

all of a sudden, my deleted emails are not going into my Trash file. They are not spam. They are just emails I've already read.

Again, all of a sudden I have a Spam folder which I do not need or want. I want my Trash folder back and I want to be able delete my emails into that folder.

Right now, and this is new, when I delete an email it completely disappears.