Thunderbird Community Forum

Dear Ladies and Gentlemen,

the last few days my new mails didn’t arrive, perhaps because I tried to introduce new digital items. Please tell me how I can use thunderbird to get my mails; perhaps I have to change my settings. I find it strange that this occurs after I did a donation to you….

Regards,

Agnes Haffner

My ISP changed us to another mail provider. So I created a new version of my existing email with different server settings, then restored my email backup. I did this all offline and it was successful. All my emails and folders were there.

Next, I went online to download new email, after which all of the messages and folders from the backup were removed (overwritten). I've tried repeating the process by removing the new account and reinstalling it, but I can't get my old emails and folders back. This is a significant problem because I have over a decade of financial and legal emails in the backup. I have tried a number of the solutions posted in the Community but have not been successful in getting my emails back. I'm using Windows 10 and Thunderbird 115.10.1.

Any insights are most appreciated.

The default font I have been using in replying to messages used to be in the same as what was designated in the Composition settings. Now, with the EnhancedReplyHeaders extension, the default font is always "Variable Width," no matter what I do with the Composition settings. What do I need to do, to have the default Reply font be the same as that specified in the Composition settings? Thanks,

- Alan

I recently upgraded to version 115.10.1 and it is driving me utterly insane. It repeatedly turns on threading. I turn it off for a folder, next time I log in it's on again. I turn it off in a folder and copy that setting to all other folders, but it turns itself on again. Others say turn it off in Settings/Appearance. But I don't seem to have Settings/Appearance.

How do I stop this? Or is there a way to find out what version I was originally running and go back to that. I hadn't upgraded for a good while but my old version was much better. This one is also really slow and I hate the tiny text.

I'm running Thunderbird v.115.10.1 on a Mac. All of a sudden, I am getting the following error message when I open up TB or check email: "Sending of password for user did not succeed. Mail server pop.earthlink.net responded: Internal error”. If I exit TB and log back in, I usually don't get the error message again and TB downloads incoming emails. I have no problem sending emails. It is still usable, but annoying because it happens 75% of the time. Any help is greatly appreciated. Thank you. -Dave

Within the last 6 weeks I migrated to Win11. I migrated my apps that would work and Thunderbird also. Got a recent update of TB. Finally MOSTLY disabled the bloody awful thread thing in TB (seems to be folder specific??!).

But ever since running on Win 11, I cannot stop TB from marking my messages as read even if I have never opened them. Even If I never use another device to connect with email. I try things and sometimes it works for like a day and then poof! : any email that comes in is read as per TB.

It is killing me. I run my biz on email and if it is unread I give it low priority. But turns out it is marked read without any action from me. I get a LOT of emails.

Really! I do no want to migrate to another email program.

I am fluent with regedit and can hack a .ini file. Point me in the right direction please.

help!

Thunderbird is not connecting with Xfinity Comcast for sending or receiving emails at gpenkala@comcast.net . This combination was working fine for decades. Last Friday (Jun 12) was the last email I received in Thunderbird. I can view current emails on the Xfinity website, but these are not being transferred to my Thunderbird account anymore, These are the error messages:

"Sending of the message failed.

Unable to authenticate to Outgoing server (SMTP) smtp.comcast.net. Please check the password and verify the 'Authentication method' in 'Account Settings | Outgoing server (SMTP)'." "Sending of the message failed. An error occurred while sending mail: Outgoing server (SMTP) error. The server responded: resomta-c2p-555483.sys.comcast.net resomta-c2p-555483.sys.comcast.net Excessive failed authentication, ESMTP server temporarily not available."

Can you tell me what configurations I should be using within Thunderbird for Incoming and Outgoing Servers?

My reddit post is here: https://www.reddit.com/r/Thunderbird/s/lM11YcRIIT

Hello,

I'm confused and slightly concerned.

Through no deliberate action by me, Thunderbird DOWNGRADED itself from the May 2026 standard release version to an AUGUST 2025 ESR(Extended Support Release) version.

UPDATE: the next application restart brought the ESR version up to date, but why was I forced onto the ESR version?!

What could have pissibly triggered this? I don't want or need ESR, and without knowing the cause, I have e no guarantee it won't happen again. Worst if all, everywhere I look, there is zero explanation for this. It appears to be fairly unprecedented.

My original installer for 102.15.1 was downloaded from the official Thunderbird site in 2025.

The sequence of events:

• I've had Thunderbird version 102.15.1 installed for awhile, but wasn't using it.
• Ysterday I opened it and connected an account.
• Today I noticed it hadn't auto-updated, so I went into the settings and clicked on the 'check for updates'.
• this brought it up to v115.10.1.
• Its success was demonstrated by me being sent to this URL after it opened: https://www.thunderbird.net/en-US/thu.../?locale=en-US&version=115.10.1&channel=release&oldversion=102.15.1(https://www.thunderbird.net/en-US/thunderbird/115.0/whatsnew/?locale=en-US&version=115.10.1&channel=release&oldversion=102.15.1)
• An hour later, I closed Thunderbird completely hoping it would fix a sync that appeared 'stuck'.
• When I re-opened Thunderbird, I saw the small "updating" window. It was pretty surprising since I had *just* updated.
• After Thunderbird opens, after this additional "update", the URL that I'm sent to is this: https://www.thunderbird.net/en-US/thu.../?locale=en-US&version=128.14.0&channel=esr&oldversion=115.18.0(https://www.thunderbird.net/en-US/thunderbird/128.0/whatsnew/?locale=en-US&version=128.14.0&channel=esr&oldversion=115.18.0)
• Thunderbird changed to a year old ESR version!

In the last months I have received e-mails that says one thing on the subject line but the content of the e-mail is an old e-mail from before. I can see in the Inbox that the subject and corresponden is related, but when I open the e-mail the address to the sender is different than expected and the content is from another, old, e-mail. If I use the web-interface to the service provider and log on to their server, the e-mail looks OK and I can see the content that I expected to be there. The service provider can't see any issues on their side and I don't have enough knowledge about Thunderbird, or the mailing protocol, to provide additional informtion to them about possible issues. It feels like the issue is on the client side, but what do I know... This has happened 5-6 times in the last 4 months. The service provider, Telia in Sweden, changed their mail server about a year ago. I have used Thunderbird, and the same service provider, for 20+ years.

I had to update my server settings in Thunderbird since I changed my email hosting provider. I had no idea I would lose all my emails and folders I created. Is there any way to get these recovered?