Thunderbird Community Forum

Thunderbird is reporting error "could not connect to server . . . the connection was refused." However, it seems that it reports this error only when there is no new incoming message. And it does not happen consistently.

Thunderbird is version 147.0. Operating system is the current version of Windows 11 on an HP desktop workstation, new 4 months ago.

I have 4 email accounts set up in Thunderbird. Server settings for the accounts are set to check for new messages at startup and at intervals of 5 to 10 minutes depending on the account and to automatically download new messages. I have confirmed the server settings for the accounts match the settings specified by the ISP. When there is a new message to be downloaded it seems that it does, in fact, connect automatically to the server and download when Thunderbird does its check for new messages at startup or specified intervals.

When I have open the Inbox for an account and click on the "Get Messages" icon or right-click on the account name and then click on "Get Messages" I usually promptly see at the bottom of the window the messages "Host contacted . . . sending login information . . . Checking inbox for new messages . . . there are no new messages to download." That is true even if I do that within seconds of receiving the "could not connect" error. But sometimes there is a delay of many seconds before the "host contacted . . ." message, and occasionally I never get that response to the click to get messages. When I click to "get messages" I never see the "could not connect" error even if the "host contacted" message does not appear.

I have set to show an alert and play a sound when new messages arrive. The same sound is played when the "could not connect to server . . ." error is displayed. The result is the sound may be played every 5-10 minutes. I can tell that this issue does not happen consistently because I might go for several hours, or even all day, without the sound and without the error message. The occurrence or absence of the error seems to be completely random and unrelated to what I may have open on the computer.

Since I do seem to be receiving messages without a delay in delivery this is perhaps no more than an annoyance, but I would prefer to avoid the annoyance. This is not happening on other computers here which are using Thunderbird.

I've read this is a common issue but hoping maybe things have changed? Trying to make a filter that says move to the junk folder email where subject starts [SPAM] (the hosting service adds that) UNLESS the address is in an address book, BUT I also need to accept everything from numerous domains. I see work arounds "if the address ends in @somedomain.com" but then I'd have to do that for every domain I want to receive from. Any email from any address where I have put *@domain.com in my address book should be let through. But I know TB doesn't accept wild cards in the address book. There MUST be some way around this? Thanks.

I can no longer send emails. I can send them through mail web browser and was in touch with their technical support and the problem is not on their end. The message I get when trying to send an email is: "Sending of message failed. The message could not be sent because connecting to outgoing server(SMTP) Promail.ptd.net failed. The server may be unavailable or is refusing STMP connections. Please verify that your outgoing server (STMP) settings are correct and try again". I checked my outgoing server settings and they are correct. I started Thunderbird in Troubleshoot mode and the problem still occurs. I started my Windows 10 in Safe Mode and the problem still occurs.

We have Thunderbird installed on 2 computers and, for the last 3 days, we have been to receive, but not send email. We can log in to our email provider online and send from there with no problem, so it's strictly a Thunderbird issue. We use Graceba/WoW for our email/internet, windows firewall, PC Matic AntiVirus, Windows 11, and Thunderbird version 147.0 (this information is the same for both computers). When we try to send an email with Thunderbird, the following error message pops up: "Sending of the message failed. The message could not be sent because connecting to Outgoing server (SMTP) smtp.graceba.net failed. The server may be unavailable or is refusing SMTP connections. Please verify that your Outgoing server (SMTP) settings are correct and try again." Our outgoing server settings are correct; nothing has changed and no updates have been done. Something happened over the course of a day 3 days ago (it was fine in the morning and not fine in the afternoon) that caused us to not be able to send email. Please help!

On my PC Thunderbirds sending/receiving mail says the mail server refused my connection. My laptop works fine. I have duplicated my laptops in/out specifications onto the PC but still nothing works. Spectrum says everything on their end is fine but can't vouch for roadrunner who is the rr in my mail address of ca.rr.com. All this started about 4 days ago. Any ideas on what to try next? Thanks.

Hello, My SMTP server uses Let's Encrypt certificate. The website with the same domain has no certificate. Thunderbird refuses to connect to my SMTP server. Test connection to the server (STARTTLS) in account settings sais "The secure connection to the server failed" (or similar. I see bg localization). Another server with Let's Encrypt certificate. Test pases. Clicking View certificate shows webserver cert (from DigiCert Inc).

I can't send emails! :)

Regards! Valentin

On January 1 my desktop version stopped downloading my GMAIL but my other non gmail are still downloading

I use Windows 10 and the version of Thunderbird is 147.0 64 bit

What can I do to fix this?

1. I've drafted an email, then hit save / closed the email and opted to "save changes". 2. I try to edit that email, but it is just "flashing" in the preview screen. I right click on it to "edit draft message", but that just brings up a blank email. 3. The status in the bottom left of the screen shows "loading message..." "downloading message", repeatedly. 4. It was working fine earlier in the week, but Thunderbird Desktop Version 140.7.0esr | Released January 13, 2026, seems to be when the problem started?

Thunderbird has suddenly started autocorrecting a particular word in my emails. I type the word "Ronnie" a lot and for no apparent reason, a window with "Rog" and an X comes up and it autocorrects to "Rognie" - see attached screenshots.

I've looked online and someone suggested it could be something to do with my address book but it happens when I am composing the email itself.

My name is Roger and I sometimes sign off emails "Rog" but this autocorrection has only just started happening and I can get rid of it.

AnMoS Tahoe 26.2y ideas, anyone?

Just installed TB 147 under Windows.

Previously, there was a menu item File/Compact Folders (plural).

It is now (at least on my machine) replaced with File/Compact Folder (singular), which only compacts the currently active folder. I cannot now find a way to compact all folders at once.

What am I missing?

I have Thunderbird on my Omen 35L on Win 11. Thunderbird CANNOT CONNECT to Comcast to send an email. This was not a problem on Win10. I have done ALL the settings fixes and NOTHING WORKS. Other mail provider accounts send OK (e.g. Site Ground). This is unique to Win 11 and Comcast.

Hello, I am using TB 140.7.0esr. I have five email accounts in TB and all send emails but one. This one email receives IMAP emails, but will not send. All emails accounts are hosted on Godaddy Office 365. The one I am having issues keeps popping up the dialog box to enter password when sending. When I click on the button to add a new passoword, TB just tries sending again. It never shows the popup to enter the new password. I have deleted this account and installed new, still same issue, only on this one email acount.

Thank you, JR

Seit kurzem, ich glaube seit dem letzten Update, werden mir Anhänge (in meinem Fall automatisch hinzugefügte Anhänge von WISO Mein Büro) immer mit dem Namen des Pfades verschickt, wo die Datei vorübergehend gespeichert wird. Fürher hat es immer einen kurzen Namen (Rechnung Nr. XY) genommen. Ist das jetzt ein Problem von Thunderbird oder WISO? Kennt jemand das Problem?

Hi, I am trying to export a calendar from a Windows 10 PC into a Lubuntu PC. The exported Home.ics file is about 217KB. At stage 4 in the import process (which shows the file name correctly) a message in red says "No importable items found in the file" . In the main area it says "Loading items" but nothing happens. Am I missing something here? Thanks

Why did retrieving messages suddenly stop. It was working yesterday and I made no changes to anything. I can send successfully. I am using Shaw/Rogers Pop server.

Why does "test connection to server" fail?

I've recently installed Thunderbird and configured it to connect to a few of the email accounts I've setup. For gmail servers, everything seems to work fine. For a locally run hMailServer server, I can connect, download messages, and even send messages - sort of.

When I try to send an email through the hMailServer account, the message sends correctly: it arrives at the other address quite quickly, and I can see in the server's logs where it connected via SMTP, transmitted the message, received a "250 Queued" response, sent QUIT to log off, and got the "221 goodbye". However the Thunderbird UI itself never progresses past the Sending Message dialog: the status stays at Sending message... and the progress bar is full. I can hit cancel and it prompts to delete the draft, etc., but either way, the message has been successfully sent. This doesn't happen with other accounts, so I'm curious what I need to do to get this to go away or send correctly....

I'm using Thunderbird 147.

I use Thunderbird 115.18.0 on a Windows 7 machine. I wish to transfer all my Thunderbird data to a machine running Linux Mint 21.3 which has Thunderbird 128.12.0esr. I have not been successful after many tries. Could this be because the Thunderbird revisions are different? If so, can I get 115.18.0 to install on my Mint machine? If not how should I proceed? I have already tried creating a new .thunderbird directory with ********.default directory from the other machine. I have also tried a new .thunderbird directory with a the ********default-release directory as directed by one site.

I have the same original problem as https://support.mozilla.org/en-US/questions/1508740 , and from the same time period, but across 4 of 5 email addresses, with additional problems. All given answers then & now on this website have completely failed me.

I have 4 emails on the same server, which use IMAP, so there is no way for me to adjust any msg retrieval settings, because they don't exist. Surprisingly, one of these 4 emails actually does work in sending & receiving, but I got different error with it, just now! I also have one gmail affected by this original 2 year old problem, as well.

Closing program, restarting computer, and downloading TB updates all do not work. I uninstalled/reinstalled TB, and all of my profiles & emails were surprisingly intact with no deletes (yes, I backed them up in another folder first), and the problem persists upon reinstall of TB, on the exact same emails as the original problem. Antivirus & firewalls are off. Server said it wasn't them. I'm using Windows 11, McAfee antivirus, and the newest TB dld is Eclipse.

There is no distinct alphanumeric error message for the oldest problem, just the usual "Login to server with username failed. Retry/Enter New Password/Cancel." All passwords are correct. None of my passwords are "saved" in the TB program, and I'm having trouble locating where to tell it to do otherwise.

Screencap and copy/paste attempts to grab second error message failed, but it looked like "RETR failed, one message expunged." So far, it's a one-time error, which I can live with. All emails for that ONE working email are fine.

When I attempt to sign into Google, it takes me to a troubleshooting page https://support.google.com/accounts/answer/32050?hl=en asking me to clear cache & cookies, if I'm using Chrome (which I'm not), instead of just a login to retrieve my gmail.

My emails have been sitting on the servers for 2 YEARS and I am at my wits' end - please help!!!