Thunderbird Community Forum

After using Thunderbird for many years, suddenly when I try to send an email, I get the error message "daily user sending limit exceeded". Apparently, I was the victim of a phishing hack yesterday, where a fictious email was send to everyone on my contact list. I have not been able to notify anyone because I can't send emails.

Hi I am Unable to send e-mails (only receive) after adding a 3rd account to my thunderbird, a microsoft e-mail (the other 2 are gmx and my old work e-mail). This is my private laptop. I tried tons of troubleshootings incl. deleting passwords, triple checking all settings (they are all correct), but I always get a pop up with "Login to server smtp.office365.com with username ... failed" when trying to send an e-mail. When I click on enter new password it just tries to send the e-mail again, which fails, so unable to enter anything.

I keep getting the following error when trying to download emails from yahoo.mail: Authentication failure while connecting to server pop.mail.yahoo.com Have hundreds of emails sitting in yahoo.mail that I need to load onto my desktop. Any help is appreciated!

When I try to send an email, I get the following response. Sending of the message failed. An error occurred while sending mail. The mail server responded: invalid user ID or password. Please verify that your email address is correct in your account settings and try again. Have looked in account settings and cannot see a password anywhere. Email address is correct Help please Carol

Today when I started Thunderbird two of my email accounts are Highlighted in RED with a RED Triangle at the end of the email address.

Both accounts are from Spectrum. My other email accounts from another provider are OKAY.

I am not able to retrieve or send emails on these two accounts. I can get my emails from both accounts when I use Spectrum Webmail. So it looks like the account information is correct.

How do I fix this?

I've been using Thunderbird on Windows 10 since last year sometime. Currently I'm on version 151.0.1.

I've 4 x mailboxes here and since yesterday, 3 of them show me an unusual message when checking for emails. I tried attaching a screenshot but although the screenshot uploaded, I couldn't find a way to insert it here. But the message says Unable to write the email to the mailbox and asks me to check if I've write privileges (which I have) and to cheek the available disk space.(currently 101GB free).

The message is happening 2 or 3 times each day and lasts for about half an hour, then everything works fine again. Has anyone else seen this??

Can't download messages on one of my computers. Account icons show locked, I think. See attached file. Downloads were working but now can't download anything newer than 01 June. How can I "unlock" the accounts? All my other computers are downloading messages just fine.

I've been a Thunderbird user for years without problem. However, since May 22, three specific messages continually reappear after deleting them from my Inbox.

I keep my Inbox empty and it stays that way, except for these 3 messages. Removing them from the Trash folder has not solved the problem.

My email provider is netaddress.com via POP3 account. I signed on to look at my inbox on their site via a browser, and the messages aren't there.

I have tried repairing and compacting the inbox, but the messages continue t reappear.

Do you have any other suggestions?

TIA.

ChuckM

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?

One emails will not download from server. Using the repair folder it says folder is busy wait until finish. All other emails work fine. One email only keeps going back. Thankyou

I have used Thunderbird (Windows 11 PC) as my email application with my Road Runner / Time Warner / Spectrum email account for over 20 years. As recently as a week ago I could send emails. Now sending fails with this message - "Sending of the message failed. The message could not be sent because the connection to Outgoing server (SMTP) mail.twc.com timed out. Try again.". No problem receiving emails in Thunderbird. I can send emails if I log into Spectrum.net in a browser and I can send emails from my Android phone. All server settings did not change and match those that the Spectrum web site says to use. Thunderbird is up to date - 140.11.1esr (64-bit). Windows is also up to date. Spectrum tech support was no help. Thanks

Can't get email from Comcast server any more & a lot of existing emails disappeared. Was on the phone with them & reset ports & checked other things but it didn't work. I can read them at Comcast's site & also send & get them there. Also can you help me forward my email to another email program?

I accidentally deleted a good number of my emails from my local Pop3 server account. I don't delete my emails from my gmail server so I can just redownload all my emails but cannot remember the prefix needed to do it.

If I recall correctly I go under settings for my email account, then go to server settings and add the prefix to my email shown in the Username field under the Pop Mail Server Section.

Can anyone remind me of the prefix?

It was like restore:[my email] or all:[my email].

I should have made a note of it as I cannot find it anywhere online now.

I think I've tried everything to figure out why Thunderbird will not send emails.

Yes there was an update the last week of May to version 140.11.1esr (64-bit).

Yes the incoming and outgoing mail server info gibes with my ISP (Shaw) - added pix

Yes have done the necessary adjustments to Windows Defender and Firewall.

Yes I have increased mail.news.tcptimeout because occasionally have received message that "Outgoing server

• SMTP" mail.shaw.ca timed out. Try again. Yes I have indeed tried again.

Yes I have called Shaw and they will not offer any suggestions because TB is a third-party.

What's left to try? A version reversion? Thunderbird has been so stable for so long. I even considered Betterbird but it uses the same profile so............

Thanks.

thunderbird refuses to connect with my email account. it says, either the name is wrong or the passwort, or the settings. name and pssword is proofed, so its the settings. where can i find them, and what is to do ?

Hello, My Provider is vodafone. Since you updated Thunderbird, i can't send emails. This Problem exist since about 2 Month. Vodafone cant help me, because they said, it is your Problem. I need very quick help. I need emails for my business. Thanks

I've been seeing a doubling of *some* incoming messages, where a duplicate message comes very soon after the first one. For example, two incoming messages were received at:

Sun, 07 Jun 2026 14:03:10 +0000

Sun, 07 Jun 2026 14:04:31 +0000

So the second message came in about 1 minute and 21 seconds after the first, and not because of anything I did (as far as I know). But then that was it, no third message came in.

This isn't really a bug, as nothing is harmed, just a repeated message. Any thoughts would be appreciated.

Have been successfully running Thunderbird for many years on Windows 10 on 2 different private computers. Within the last week both computers unable to send and receive messagees. BT E mail account is absolutely fine as can access it via webmail and via Android e mail app on my phone. Login details have not been changed. Have tried updating to 150.1 no joy. When trying to send a message we receive Send Message Error immediately but with no explanation as per attached image.