Thunderbird Community Forum

Hello

i am struggling with TB as it always uses the default email of a server account.

Instead, i would like to use different accounts based on the recipients

I could not find an extension with this behavior.

For example, I would like all email exchanged (sent & received) to a domain ( @thatcompany.com ) to use a given account alias (myalias.email@proton.me)

Thanks for all assistance

I am trying to setup Thunderbird using one User-ID and PWD combination, with multiple email addreses (Spectrum ISP). I have executed the Profile Manager but it seems to use the email address provided as the account access User-ID. This is not working in my scenario. I need to provide to Thunderbird User-ID and PWD credentials once, and retrieve/send email for multiple email addresses. My ISP (Spectrum) supports multiple email addresses (up-to 5) that are associated with one User-ID and PWD.

Thunderbird suddenly will not download my mail. Instead, it stops and resets the connection to the POP server and gives me a pop-up message saying: 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've deleted almost all messages in my Inbox and everything in Trash. I've gone to my webmail and deleted any messages I don't recognize on the server. I turned off my firewall. And I checked my settings, which seem to be fine. All to no avail. Thunderbird still won't download my mail and gives me the same message over and over.

What do I do now? Please help!

I am not receiving emails today? on quick examination I was directed to 'error console'..where is that? Have I done something wrong-- Yesterday I tried to access my bt emails on my mobile phone and had to change password has that stimied the receipt of emails to computer?

Hi there,

This one almost gave me a heart attack, naturally. It's pretty simple to reproduce:

1. Start a new reply to an existing email from someone. 2. Write for a while, stop. Thunderbird will save the message by uploading it to the IMAP server. 3. Open Gmail with the web or mobile app. The message will appear in the reply thread, without a "draft" label, as if it was sent to the recipient. 4. Edit the email again. Send. 5. Thunderbird will delete previous version. This is visible in the Gmail web client as "X deleted messages in this conversation." label and that's how I discovered it.

The recipient _appears_ to only see the latest version, but that's still kinda scary because it seemed like the draft was sent without the user clicking "Send".

Thanks!

Although 1900 or more messages are reported, Thunderbird only downloads a few - 18 once, 10 and now only 2 - before stopping. After deleting all messages, stopping and restarting Thunderbird, it then downloads the same few - or less - again, no new ones, and the are very old ones. Screenshot shows current situation - several identical messages only. Version 140.8.1 esr on Windows 11 - both up to date. I don't know what esr means !

I am an emeritus professor using the UVM email account X@uvm.edu<mailto:X@uvm.edu>, which I have used for many years. I use Mozilla Thunderbird (current version, “Eclipse”) as my email client and my account is configured for UVM’s Microsoft 365/Exchange Online service. After my most recent required yearly password change, although I can still receive email in Thunderbird, I can no longer send email. When I attempt to send a message, I consistently see this error: “Login to account ‘smtp.office365.com’ failed. Login to server smtp.office365.com with username tosler@uvm.edu<mailto:X@uvm.edu> failed.” Here are my current settings:

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Incoming (IMAP):

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Server: outlook.office365.com

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Port: 993

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Connection security: SSL/TLS

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Authentication method: OAuth2

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Username: tosler@uvm.edu

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Outgoing (SMTP):

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Server: smtp.office365.com (I have also tested smtp.uvm.edu with the same result)

    *

Port: 587

    *

Connection security: STARTTLS

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Authentication method: OAuth2

    *

Username: X@uvm.edu

I have reinstalled Thunderbird, and I have removed all saved passwords and tokens for outlook.office365.com and smtp.office365.com, restarted the program, and completed the Microsoft/UVM sign‑in prompt again. IMAP continues to work and mail arrives normally, but SMTP authentication still fails with the error above. Because:

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The configuration matches Microsoft 365/Exchange Online client‑submission settings, and

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IMAP with OAuth2 works, while SMTP with OAuth2 fails,

it appears that this may be a server‑side policy or mailbox setting, rather than a client configuration problem. What are my options? Does the University of Vermont have to change some setting on their end on my behalf? Thanks. -turner

(PII redacted by moderator)

After recent update I can no longer send email on any of my accounts. A message popped up when I opened Thunderbird after the update stating I would need to change some settings, but message disappeared before I could read it all and could make changes. I need to know what settings I need to change to restore outgoing mail ability. my Email accounts are Gmail and Yahoo.

Using TB 140.8.1 esr(64 bit) on Win11 Home desktop. My internet speed: About 40 Mbps up and down. All routine Win and TB updates installed when available. No changes in configuration, accounts, settings etc. except installing routine updates to TB and Win11. No problem with sending/receiving email. Sent mails go out immediately and appear right away in my sent folder. No problem receiving USENET news new postings to subscribed groups. I'm subscribed to 3 groups, using news.eternal-september.org. It used to be that when I wrote a reply to a post in a thread the msg would be sent within a few seconds. Recently and consistently, when I post to a group, pop-up notification tells me msg is being assembled. But progress appears to stall and msg often takes an hr. or more to appear in sent folder. Sometimes, it never appears in my sent folder but I can see it was sent because subsequent new postings to the same thread often cite my text and/or reply to it. My sent configuration: outgoing server: smtp.gmail.com port: 465 user name: my gmail email address - which works fine using google's web interface or TB authentication: OAuth2 connection security: SSL/TLS Any idea what's wrong? Any suggestions what to try to get back to prompt processing of sent postings to subscribed USENET groups?

I have been using Thunderbird with two POP3 Hotmail accounts for some time and I am trying to set up a third account with exactly the same configuration. However, both the automatic and the manual configurations failed. The new account receives mail, but the outgoing smtp server config seems to have a problem. Sending messages times out or keeps prompting for a new password.

The Hotmail account has POP3 and IMAP enabled. Thunderbird is set to receive all cookies. I cleared history and cache after every attempt and also temporarily disabled the firewall.

Any suggestions about what the problem could be?

This started happening about a month ago, without me changing my settings, which are to retain all emails unless manually deleted. Probably relatedly, copies of sent emails are not saved in the Sent folder. This is my account on yahoo.co.uk - all the emails are available when I go to yahoo through my browser, so it is just Thunderbird that is not ertaining them. I automatically accept Thuderbird software updates (now 148.0.1)

Hi there, it seems I'm suffering from the same problems as others in several countries. I have also not been able to access my gmx.com account via Thunderbird for about a week now. I live in Belgium and use a Proton VPN, in case this is relevant. I can't find how to delete cookies in history, nor any other potential solutions to the problem. Any help offered is greatly appreciated! Best, Doreen

Thunderbird version number: 148.0.1 Mail provider: Yahoo Client OS: Windows 10

The issue and steps I tried to resolve: On 1 Jan 2026 I switched from Outlook client on my Windows 10 PC to Thunderbird 146.0.1. I did not import any user data from Outlook but started with a clean install of TB for the new year. I use yahoo.com with POP3 as my email provider. Server Settings: Server Name "pop.mail.yahoo.com", port 995, SSL/TLS, OAuth2 Outgoing Server: Server Name "smtp.mail.yahoo.com", port 465, SSL/TLS, OAuth2

it all worked fine and I was very happy with the setup. Then from early to mid-February I was unable to use my computer. When I finally accessed Thunderbird again, it connected to Yahoo and showed that approximately 800 email messages would be downloaded and started downloading them. After downloading about 100 messages, Thunderbird timed out and I haven't been able to get it to work since.

I have read and followed or tried to follow these articles plus others that I may have forgotten about (not listed in any particular order) - OAuth2 Authentication for Yahoo, AOL and ATT | Thunderbird Help - including all the steps in Please check the following before asking for support - POP access settings and instructions for Yahoo Mail | Yahoo Help - Automatic Account Configuration | Thunderbird Help - Manual Account Configuration | Thunderbird Help - Thunderbird and Yahoo | Thunderbird Help - Send and receive messages in Thunderbird | Thunderbird Help - Can no longer get emails | Thunderbird Support Forum | Mozilla Support - Emails suddenly stopped downloading to Thunderbird 140.2.1esr | Thunderbird Support Forum - Get Messages | Thunderbird Support Forum | Mozilla Support - Cannot receive messages | Thunderbird Help - Problem with Thunderbird working with Yahoo Mail acccounts. | Thunderbird Support Forum

I have removed all messages from the Yahoo inbox and tried to find one or more messages that may be affecting the download. I don't know the best way to determine that.

I use Windows Defender for my antivirus. I don't see anything in Defender that blocks or scans email messages which would prevent downloads, although I could be wrong about that. if this might be the issue, please provide some guidance about how to check Defender.

I have uninstalled and re-installed Thunderbird. In the process I downloaded the setup file for Thunderbird Setup 148.0 and installed that version. It later auto-updated to 148.0.1. Before installation, I removed all external connections from my Yahoo account and completely removed Thunderbird from my PC, including the profile and profile.ini. When I reinstall and switch the account to POP3, Thunderbird captures the App password from Yahoo and connects just fine. But it still times out while attempting the first download of a message. The first several times it timed out, an error message was displayed but now it doesn't show anything. Except no messages are downloaded.

At this point, I don't know what else to try. Since I don't have much experience with Thunderbird, I don't know how to troubleshoot the process (logs to look at, etc.). I don't want to go back to Outlook but I need the email client to work and download messages. Any help would be much appreciated.