Thunderbird Community Forum

Thunderbird version 148.0.1 will not send outbound emails since updated to OAuth2. Error message is Unable to Authentic Outgoing server (SMTP) Email account will allow inbound mail , but will not send mail. Have worked through all published troubleshooting steps. Extremely frustrating!

The details were given in my question. I am receiving the following message in all my incoming e-mails and have no way of replying to the sender because REPLY and REPLY ALL no longer appear in my Thunderbird e-mail task bar. Here is the message I receive with each incoming e-mail: "A unique identity matching the From address was not found.. This message will be sent using the current From field and settings from identity lonearranger <lonearranger@telus.net>" How can I get rid of this message and go back to seeing REPLY and REPLY ALL in my task bar?

error message follows

sending message failed.

An error occurred while sending mail. The mail server responded: Authentication required please verify that your email address is correct in your account settings and try again.

The email address is correct. What is going on?

Good morning,

I have a Thunderbird desktop client connected to an email on a Smartermail server via IMAP. Receiving mail just fine, but sent mail stalled on the send then gives the following error.

Your message was sent but a copy was not placed in your sent folder (Sent Items) due to network or file access errors. You can retry or save the message locally to Local Folders/Sent Items-chrissy@fruitacoop.com.

I can switch it to save to a local sent folder, but that is not a viable permanent solution. I have searched and followed all suggested troubleshooting steps I could find in the community forums without success.

Steps tried: - completely removed the account and added it back - completely removed Thunderbird and all app data, reinstalled - Tried many suggested "copies and folders" configurations

All unsuccessful. If anyone has had this issue and has any insight into a soluution, I would be forever grateful.

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.

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.

サンダーバードで受信は出来ますが、送信ができなくなりました。 「メッセージを宗しおんできませんでした。 送信（SMTP）サーバー******に接続できなかったため、メッセージを送信できませんでした。サーバーが利用できないか、SMTP接続が拒否された可能性があります。送信（SMTP）サーバーの設定が正しいか確認し、再度試してください。」と表示されます。SMTPサーバーを編集してみましたが治りません。どうすれば良いですか？

I have created folders that I want specific emails to be put in when they arrive. But I don't know where to create these rules. Creating the folders is easy but how do I create a rule that tells Thunderbird which folder to put emails from specific people/businesses etc

I have Thunderbird working well on my desktop. I am trying to add it to my laptop. I am unable to get the setup accepted. the message I get is failure likely caused by wrong name or password. The name and password obviously work on my desk top computer.

Bei Absenden der email (wilhelm-wisch@t-online.de) folgende Fehlermeldung: "Senden der Nachricht fehlgeschlagen. Fehler beim Senden der Nachricht, SMTP-Server Fehler. Der Mail-Server antwortete: IP=38.246.32.196 - Your address is blocked.

Please help, thank you!

After thunderbird starts, i see the txt at the lower left "sending login information" followed by "there are no new messages"....but a couples of seconds later, a red dot appears on the blue Tbird icon on the task bar, indicating a number of new messages received....why do these two indicators contradict each other ?

I think this began to happen when I moved my profile from win10 to a new machine on win11. Everything else seems to work fine, but I don't think that txt msg at the lower left after initialization has ever said there are new messages....since moving to the new machine & OS.

Looks like the txt portion of that message is getting information from somewhere different than the red dot on the taskbar icon is ?

I have 2 Verizon accounts in Thunderbird. One of them works fine, the other one gets the emails that were sent to the first one. It's like there is a forwarding address sent on the first email that is sending them to the second one. I removed the accounts completely, uninstalled and re-installed the Thunderbird and I still have the same problem. On webmail, on aol.com, the email addresses work perfectly fine.

It's been almost a week now, and my 2 Microsoft email accounts will not connect to Thunderbird anymore. All was fine for years, but something changed that I can't figure out!?! I have gone to my Microsoft email server and checked that my passwords still work. I even updated one and it works on Microsoft server but not Thunderbird's!?!? I even deleted one email account from Thunder bird to re-install it, but when I tried a fresh re-install Thunderbird still won't connect to Microsoft server??? I'm at my wits end, and may abandon Thunderbird completely if someone there doesn't help me connect!!!

I have installed Mozilla ThunderBird Previously on many machines. Am Familiar with Incoming Email Servers and OutGoing Email Servers ... Also special ports ... POP ... and .... SMTP ... IMAP ... ETC ... GBGB On this Machine ... Dell Latitude ... 128 GB SSD ... 8GB RAM I have Mozilla ThunderBird Installed for as Single Email Account ... OverstreetENGR@Juno.com

When I REPLY to Emails , THIS IS the error message that I get : Sending of the message failed. The message could not be sent because the connection to Outgoing server (SMTP) smtp.juno.com timed out. Try again.

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:

 *

Incoming (IMAP):

    *

Server: outlook.office365.com

    *

Port: 993

    *

Connection security: SSL/TLS

    *

Authentication method: OAuth2

    *

Username: tosler@uvm.edu

 *

Outgoing (SMTP):

    *

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

    *

Port: 587

    *

Connection security: STARTTLS

    *

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)