Thunderbird Community Forum

I would like to setup Thunderbird as my email client.My email service is provided by Godaddy with an Outlook account. When I am at the incoming server settings, it has my domain name, not smtp.office365.com which I tried with both authentication options (below) and with my domain name, the protocol was IMAP. I changed the port from 143 to 993. I changed security from Autodetect to SSL/TLS. For authentication, there was not an OAuth2 option, I tried Autodetect and Normal password, neither worked. And I used my domain email password. with using my domain name, it came back with an error an suffixed my domain name with :110. It stated that this was not the correct domain and there was a security issue. It is not clear how I should progress.

rentitnow@mail.com was able to be accessed thru Thunderball. BrianKrantz@mail.com says wrong credentials. I know for sure the credentials are correct. They use the identical port. What can be done?

Hi, Last week, Thunderbird stopped receiving & sending emails with CenturyLink. I can access CenturyLink emails via their website and on my android.

Using Google, it said the configuration should be changed to CenturyLink's settings. It looks like Centurylink changed the settings for legacy email "centurytel.net". I went to CenturyLink website and copied their settings the best I could.

https://www.centurylink.com/home/help/internet/email/how-to-set-up-your-email-server-settings-to-go-through-pop-and-smtp.html

1. CenturyLink website shows changes to the following settings.

       a.	Incoming Server:  POP:  pop.centurylink.net    Port: 995, Security:  SSL
       b.	Outgoing Server:  SMTP:  smtp.centurylink.net    Port:   587     TLS if available
       c.	Username:  Full email address which for me ends with @centurytel.net

2. Thunderbird settings are: (screen print attached)

        Incoming:  POP: pop.centurytel.net  Port:  995, & Security:  SSL/TLS.  
        Outgoing SMTP:   Server:  smtpauth.centurytel.net    Port:  587,  & Security:  STARTTLS

I only changed the POP and SMTP server names. The security settings could not match up exactly since the drop down options did not have SSL and TLS individually. I left the original settings Thunderbird had of SSL/TLS for incoming and STARTTLS for outgoing. A screen print of Thunderbird's original settings is attached.

After following the settings configuration setup in Thunderbird, entering my correct password, I received this Authentication error: "Unable to log in at server. Probably wrong configuration, username or password." That's as far as I can go. Thank you for any help you can provide.

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?

I have been receiving the error message quoting the SCO1 policy about reaching my sending limit every day recently. This has happened even when I have only sent 1 or 2 messages and these have only been to a handful of people.

"Sending of the message failed. The message was not sent due to exceeding the allowed number of recipients. The server responded: Policy-SC01 You’ve reached your sending limit. Don’t worry, you can send again soon.."

I have seen a previous strand where this was explained as being something imposed by the email provider not Thunderbird. However I have managed to send emails from the website of my email provider that I haven't been able to send through Thunderbird. This suggests that the previous answer was wrong. I would like to use Thunderbird so please help me sort this out.

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"?

As background, I recently migrated to Thunderbird and imported a very large number of e-mails. The issue, however, is in regard to a new e-mail that was downloaded yesterday.

The new e-mail was downloaded in a normal fashion, but when I went to look for the e-mail in the Inbox, it was no longer visible in the (although I had not moved it or deleted it).

Running a search on the sender's name finds the e-mail. It is in a thread of 6 or 7 e-mails. The search shows the e-mail is located in the Inbox, however a sort by sender name in the Inbox does not reveal the e-mail.

In the search result, I starred the e-mail (it is the only starred e-mail in my e-mail database), but a search of all my e-mail folders shows no starred e-mails at all.

I also went through all my folders and moved all e-mails into the "read" status, then found the lost e-mail using the search function and marked it as unread.

The Inbox folder shows that I have one unread e-mail in the folder, however when I filter for unread e-mails, the results are zero.

My local telephone company updated their webmail. Now I can't send or receive emails. I called support and they wanted me to change some outgoing , and incoming server settings. I can't find the incoming server, was able to change settings on outgoing server.

Thunderbird 156 wanted to keep getting a response that my business associate's email account did not exist. I had to have the recipient contact me to get Thunderbird to successfully deliver the email I first sent and responded to. Is this not some Java bug to the domain?

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!

I have been unable to send emails for two weeks. I continually get error messages such as "An error occurred while sending mail: Outgoing server (SMTP) error. The server responded: EHLO requires valid address." Another message says to check the SMTP outgoing server settings. I am using Windows 10, which has worked for several years. My email server is mail.twc.com and Spectrum. I can send emails via my iPhone or via the Spectrum webmail, but not through Thunderbird. I have examined my SMTP settings several times and have tried various combinations of settings. None has worked. Spectrum has no help and refers me to you. Can you help? Thank you, Andrew Gurian

Hi I have just set up AOL accounts for 3 email addresses on Thunderbird. I have set them up as pop accounts and each account can receive emails and send emails ok but the really strange thing is they won't send from one AOL email address to another AOL email address which is something we quite often do as as family. All have pop.aol.com and port 995 along with smtp.aol.com and port 465. Hopefully someone will know what is going on.

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'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?

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.