Thunderbird Community Forum

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??

I have two Exchange accounts with the same domain. When I added the second one it appeared in the account settings with all the correct information. However the account only has an 'Archive' folder and none of the other emails show in Thunderbird. Any ideas?

Hi Today, several emails that I have received, which I think were sent from an Outlook account, have, instead of what I would expect to see as the sender's address under correspondents, have Microsoft account team <account-security-noreply@accountprotection.microsoft.com> When I click on the email, I can see the genuine sender's address This has only happened today At least one of the emails that I received came from someone that I know uses Outlook Any ideas? Thanks

My Thunderbird version is 153.2. My email provider is Yahoo.. I use the POP protocol and have set it up so that messages are left on the server for this particular email address because I want to hang on to several important emails. I am not sure if I should be checking "Until I delete them" but it is checked right now. Leave messages on server for X number of days is unchecked. I also have a few other Yahoo mail addresses on Thunderbird also set up using POP but the messages are set up to be deleted on the server so they seem ok so far.

Basically when I delete messages in Thunderbird, it also deletes my messages in my Yahoo webmail inbox and it goes to the trash. When I delete messages directly in my Yahoo webmail, nothing happens. So I then transfer the emails that ended up in trash of my Yahoo webmail to my inbox and they are of course downloaded again to Thunderbird. When I delete these emails in Thunderbird thinking that nothing will happen in my webmail since it is set up to POP and messages left on the server, the messages get deleted again, causing an endless cycle of transferring emails to inbox, downloading them on Thunderbird, deleting the unwanted emails on TB, then seeing all my other emails disappear on my Yahoo webmail inbox.

It started a few days ago. There was a random glitch (not sure if it was on Yahoo's end) that led to the OAuth dialog window popping up every time TB downloads mail from Yahoo. Initially I didn't handle this properly and it led my inbox emails going into my other Yahoo mail accounts. I have finally fixed that glitch and emails appear to be downloading properly to their respective inboxes. But I cannot seem to figure out what is causing my emails to be deleted from the POP server. Should I be unchecking "Until I delete them"?

Greenby Support wants a screenshot of Thunderbird Outgoing Server (SMTP) which I can't find via the App menu or any other means of searching. So I do not know which version we have re your question below and I have chosen one shown at random to allow me to submit my question

I choose to use POP not IMAP. Yesterday morning, messages downloaded as normal, no problem. Yesterday afternoon, they did not download and I received this message "Unable to write the email to the mailbox. Make sure the file system allows you write privileges, and you have enough disk space to copy the mailbox." I had done nothing at all to my system in the meanwhile, as far as I am aware. I have tried deleting a lot of old emails from my inbox, and emptying the 'Deleted' folder. Any suggestions very welcome.

I have the latest T-bird installed on a latest version linux Mint laptop and occasionally get puzzling errors on Yahoo mail.

Mostly it all works, but Yahoo email errors are often enough to be bothersome and I can't find any information on the rather obsure errors. Been this way through many t-bird and Linux releases.

My other email accounts don't seem to have a problem (gmail, outlook) on any t-bird instances. Just Yahoo mail on Linux Mint t-bird. Here are the errors:

"Please try later" and apparent timeouts on Yahoo mail (on t-bird, of course). This is obvious, but it doesn't happen on my Win 11 and Android T-bird programs.

Operation on yahoo "inbox" did not succeed. Yahoo mail server responded "p." (Yes, just "p.")

Operation on yahoo "inbox" did not succeed. Yahoo mail server responded "UID FETCH completed"

These errors don't seem to happen on Android t-bird or Win 11 t-bird on the same accounts, but I'm not on those for very long.

Any guidance would be appreciated.

Yes, this outlook account was made earlier this year. I've tried all of the "fixes" offered on here and across the internet. I'm changed to to password and got the app password. I've deleted 2FA to see if that would work. I've deleted the Oauth key and it refreshed to a new one. I've done it all and TB-sync is not available to me cus apparently now i'm right outside the app version limit.... how convenient. It's very frustrating as i really like the app and still use it to read my emails but it's very annoying to have to open the outlook app and go through all that just to send an email. I keep getting told it is possible, i've been battling this on and off for months. I cant just get a new email either as i already swapped everything to the outlook one and my work using out look as well. i am able to sync my calendar even but apparently just not my outgoing emails. I would like to transfer my email but the other email i have is a proton email and they are a whole other headache. Please help.

OS: Linux / Android

TB Version: 156.0

Current Outgoing Server Setup:

Server Name: smtp-mail.outlook.com Port: 587 Connection Security: STARTTLS Auth Method: OAuth2 Username: *****@outlook.com

Mail sent to me as cc: and/or bcc: addressee (but not as a To: addressee) is received at my ISP mail account, but Thunderbird will not retrieve them.

This has been going for a long while it seems, but I don't get much mail addressed as cc: or bcc:, so I only recently became aware of it.

My ISP webmail interface uses Roundcube. Cc: and bcc: messages sent to me show up there. I have Thunderbird 156.0 installed on two macOS 27.0 machines and Thunderbird 24.0b2 installed on Android 17 (includes all updates through Android security update of September 5, 2026). Neither of the three will retrieve the cc: or bcc: messages, but all other e-mail functions work as expected.

My ISP says it's a Thunderbird problem, but I ain't so sure. Any ideas?

“My Spectrum email address is [redacted]@charter.net. Spectrum webmail can send and Thunderbird can't receive or send. The outgoing server is mobile.charter.net and the connection times out. I tested the connection from my computer and ports 587 and 465 both respond successfully. Thunderbird is set to No Proxy. when i tried to send today, it gave me this message, "Sending of the message failed. The message could not be sent because the connection to Outgoing server (SMTP) mobile.charter.net timed out. Try again." i contacted spectrum about this and now when i try to send, it says nothing and the message never arrives.

I created a POP3 account, and no SMTP config was crested in Thunderbird. So, I tried the Add option and after filling the form the line still did not get created. Current TB version, Win 11 Pro. I have several other accounts that configured OK, all Spectrum.

Thunderbird is downloading new messages but failing to display them.

Other functionality remains active, ie I can see and open messages, delete all the contents of folders, compose and send messages, but when the software downloads new messages they simply do not display and cannot be accessed.

Not sure if it's relevant, but the message INBOX count appears to be stuck at the number 59, although more messages than that have been downloaded.

Bizarrely this is the message displayed whenever I now open the Thunderbird application (it was there when the problem first appeared and returns everytime). Out of desperation I even made a donation in the hope it would release the messages!

Thank you in advance, Steve Davidson

I am starting have problem with Yahoo mail interface with thunderbird, It is not updating yahoo mail. I stared to get message " Connection to server Pop.mail.yahoo.com timed out". What is the solution? I checked server port (995) number and Thunderbird is upto date.

Any help is appreciated

I have had Thunderbird on my Mac Monterey synced to my Comcast email address with no problems. Usually I have to enter my Comcast password when I send the first message for the day. It has caused no real problems since I obtained this computer, probably sometime in 2021. Within 2023 I obtained a Windows 10, onto which I also put Thunderbird. Last November I upgraded to Windows 11 had kept Thunderbird. I did not do the upgrade myself. The technician used Google Drive and OneDrive for backup. I added a GMAIL address on that system to my Thunderbird installation on Windows 11.

For the past week Thunderbird has been popping up a Comcast site requesting that I enter my Comcast password. This is bizarre! How can I get my Thunderbird to behave more normally on my Windows 11? Thanks in advance. The technician only did the upgrade. I did the subsequent program reinstallations.

I cannot connect Thunderbird to a primary outlook.com account. I can connect to an outlook.com alias account. I have confirmed this on two Windows 10 machines. I can connect to the primary outlook.com account from an iphone and an ipad. Is Thunderbird broken?

I use Windows 11 Pro on a desktop computer. I use Firefox (which is up to date) and Thunderbird as my email client (which is up to date). I use Zone Alarm Extreme Security as my Firewall and Anti Virus

Recently it has become a nightmare sending and receiving emails to my markhowes@btinternet.com email address. Sometimes the emails (which I know are on the bt server) don't arrive but I don't get an error message. Then later in the day I might receive loads of emails at once.

Sending emails is even more of a problem. They simply don't go. Sometimes I get a time out message, sometimes I get an incorrect password message.

Within Thunderbird there is an option to check connection to both the outgoing and incoming bt servers. Usually (but not always) connection shows as "successful".

This has been going on for a couple of months - maybe it's a coincidence but it seems to start up after a Windows automated update and then things settle down again (I think) until the next Windows monthly update.

I'm not all that computer literate so please don't suggest messing around with the Registry or other very technical solutions but if anyone can help me solve this maddening problem I would be really grateful.

I can send and receive emails on my Android phone and directly on the bt email site via my Firefox browser.

Mark