Microsoft Outlook SMTP authentication issues

Coming from https://support.mozilla.org/en-US/kb/cannot-send-messages, and https://support.mozilla.org/en-US/questions/1596545#answer-1837376 (thank you christ1) Account … (czytaj dalej)

Coming from https://support.mozilla.org/en-US/kb/cannot-send-messages, and https://support.mozilla.org/en-US/questions/1596545#answer-1837376 (thank you christ1)

Account settings attached. I don't have an active firewall. My email provider is microsoft (outlook) No antivirus installed Linux Mint 22.3 x86_64 Thunderbird 153.0esr

I have confirmed with microsoft support that the ports and such are correct, they claim thunderbird is the problem.

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I can't send or reply to emails on Thunderbird email

Sending of the message failed. An error occurred while sending mail. The mail server responded: <support+idMM51X2-RWD3K@dealerbuilt.zendesk.com>: Relay access denie… (czytaj dalej)

Sending of the message failed. An error occurred while sending mail. The mail server responded: <support+idMM51X2-RWD3K@dealerbuilt.zendesk.com>: Relay access denied. Please check the message recipient "support+idMM51X2-RWD3K@dealerbuilt.zendesk.com" and try again.


the above is the error code. I have triple checked emails, even tried sending a message to my personal email as a test and nothing.

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I am now getting this popup even though I am not trying to connect to Gmail

Hello, I use Thunderbird to retrieve my AOL mail. Starting today, when I start Thunderbird it retrieves the AOL mail and then after a couple minutes I get the attached p… (czytaj dalej)

Hello, I use Thunderbird to retrieve my AOL mail. Starting today, when I start Thunderbird it retrieves the AOL mail and then after a couple minutes I get the attached popup. I am not trying to connect Thunderbird to any Google account and I don't understand why I would get a message saying to use Google to sing in to Thunderbird. Once this popup occurs Thunderbird will not connect to AOL until I close it and restart it. I do have GMail set to forward messages my AOL address but this screen has not come up before

Any thoughts?

Thanks, John

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how to ensure my yahoo continuing yahoo mail is kept in local folders?

I just downloaded and put into mirror 'local folders' all my 100 and more folders from yahoo going back 25 years. excellent. I believe they are safe and solid as a rock … (czytaj dalej)

I just downloaded and put into mirror 'local folders' all my 100 and more folders from yahoo going back 25 years. excellent. I believe they are safe and solid as a rock now? Simple question is how to get all ongoing emails into those folders?

I did all that with an add on called importexporttoolsng which is great but does not live on and monitor new arrivals.

I've been advised to set up an archive folder and put everything in there and i will if i must, of course. but ideally maintaining the current folder structure that yahoo is moving messages into is the best way.

can it be done?

Otwarte 5

SEND button vanished after update (bug1989214)

After updating to 153.0.1esr(aarch64). the SEND button has disappeared. There's no way to send an email. (I can receive emails.) I am a Mac mini M2 Pro. OS 26.4.1 I ca… (czytaj dalej)

After updating to 153.0.1esr(aarch64). the SEND button has disappeared. There's no way to send an email. (I can receive emails.) I am a Mac mini M2 Pro. OS 26.4.1

I cannot find a link to download a previous release of Thuderbird, which was working fine until this update.

Otwarte 10 1

No button to send my emails

I started a monthly donation to Thunderbird a few hours ago and now I'm thinking it may have been a scam. Not sure, and I have sent an email to your donation email about … (czytaj dalej)

I started a monthly donation to Thunderbird a few hours ago and now I'm thinking it may have been a scam. Not sure, and I have sent an email to your donation email about this. Since I made that donation (and maybe this is a coincidence), I am not able to send any emails. I can compose an email, but there is no "send" button anymore. Can you help me with this? Thank you very much.

Rozwiązane 4 1

BUGZILLA bug feedback uses AMAZON and its reporting IP address is getting bounced

It seems it is because BUGZILLA uses the AMAZON'S service, but there is now a RANGE of IP addresses that have been blocked, and BUGZILLA have been caught up in this mess.… (czytaj dalej)

It seems it is because BUGZILLA uses the AMAZON'S service, but there is now a RANGE of IP addresses that have been blocked, and BUGZILLA have been caught up in this mess. Please let me know which board I can use to report/ask about this issue, if it is no on here..

Here is the issue research (NOTE: I have emailed the BMO_MODS email several times, but had NO RESPONSE, so want to check if others have this issue):

Based on the error message you're receiving, Microsoft is blocking emails from your IP address because it appears on their block list. This is a Microsoft-specific issue rather than an AWS problem. When you receive a 550 5.7.1 error with the S3150 code from Microsoft domains (Hotmail, Outlook), it means Microsoft's filtering systems have identified your IP address as a source of problematic traffic. Even though you're using a managed dedicated IP and haven't intentionally violated any policies, there are several reasons this could occur: The IP address may have a poor reputation due to previous usage by another customer, spam complaints from recipients, high bounce rates, or sending patterns that Microsoft's algorithms flag as suspicious. Sometimes legitimate senders get caught in these filters. To resolve this issue, you should:
  • Contact Microsoft directly using the troubleshooting link provided in the error message (mail.live.com/mail/troubleshooting.aspx) to request delisting
  • Review your email sending practices to ensure you're following best practices (proper authentication, low complaint rates, engaged recipient lists)
  • Consider contacting AWS Support to discuss your dedicated IP's reputation and whether a new IP might be warranted
  • Ensure your SPF, DKIM, and DMARC records are properly configured Microsoft maintains their own independent block lists and reputation systems, so even with AWS's managed infrastructure, you may need to work directly with Microsoft to resolve deliverability issues to their domains.
Otwarte

messages are move from inbox to trash automatically ...

TB suddenly moves messages from inbox to trash automatically without any interaction. Search through the forrum shows that it has been asked for already, see https://supp… (czytaj dalej)

TB suddenly moves messages from inbox to trash automatically without any interaction. Search through the forrum shows that it has been asked for already, see https://support.mozilla.org/en-US/questions/1588804, similar postings can also be found with you search engine.

As described in other postings, the messages are moved from Inbox to trash. When moving them back manually from trash to inbox, they are moved to trash again immediately.

  • it happens for the default account only,
  • there're no filters at all in TB,
  • junk detection is disabled,
  • Settings->General Storage is all disabled,
  • (account)->Settings->Server Settings has checked "move deleted messages to trash",
  • (account)->Settings->Storage is all disabled,
  • Inbox->Properties "Repair folder" does not help,
  • Inbox->Properties "rules is set to "use account settings" (and greyd out "do not delete messages"),
  • exactly same behaviour when starting TB in save mode,
  • manually deleting all *.msf files (for inbox) does not help,
  • manually deleting xulstore.json does not help,

Additional notes, which are not related to the problem, IMHO:

  • IMAP on port 993,
  • no other clients anywhere are connected to that account,
  • TB configured for more than 10 accounts, more than 500 folders and sub-folders,
  • host with > 16GB RAM, TB uses 3GB virt,
  • problem observerd in older TB also, at least 13x.x

I'd be happy to debug/trace the problem if someone can give me detailled insructions how to start TB with debugging. Please feel free to ask for about:config settings as they are non-ambiguous and language independent ;-)

Thanks.

Otwarte 9 59

Every new message window requires a reset to "Restore Default" every time in order to activate the send button so how do I make the "Default" mode permanent?

On my iMac, across all thunderbird email accounts, when I click on "New Message", the new window opens up with the Send button and Encrypt button blanked out. To activate… (czytaj dalej)

On my iMac, across all thunderbird email accounts, when I click on "New Message", the new window opens up with the Send button and Encrypt button blanked out. To activate the Send button, I have to right click on the Send button, then click on "Customize..." button, then click on "Restore Default Set". Next new message, same drill. This started one day ago and is a pain in the butt. How do I make the Send button live permanently?

Rozwiązane 2

CC field on Android limited to 1 recipient?

Functionality and usability issue: I use the Thunderbird for Android app as an adjunct to my desktop installation. Recently I had occasion to reply to an email in Androi… (czytaj dalej)

Functionality and usability issue: I use the Thunderbird for Android app as an adjunct to my desktop installation. Recently I had occasion to reply to an email in Android to one "to" recipient and needed to add two "cc" recipients, but found no way to add the cc recipients without deleting the existing cc recipients and having to input the entire (dynamic) group again, but then was also stymied by that. How best to handle this issue?

Other than that issue, the lack of desktop contacts synching, and the lack of spam filtering, Thunderbird for Android has been a huge help, so thanks to the developers for their dedication and hard work.

Rozwiązane 9

Password rejection by email provider

I changed my password for Greenby/Plusnet today. Now Thunderbird is unable to connect to them. The password is correct as I can enter website directly. No problems be… (czytaj dalej)

I changed my password for Greenby/Plusnet today. Now Thunderbird is unable to connect to them. The password is correct as I can enter website directly. No problems before change. Grateful for help.

Should I reinstall?

Rozwiązane 10

Hotmail personal account: IMAP OAuth2 works but SMTP OAuth2 fails with message: 535 5.7.139 “SmtpClientAuthentication is disabled for the Mailbox”

I am assisting an elderly user with a personal @hotmail.com account that receives email successfully in Thunderbird but cannot send. I have confirmed they can send and re… (czytaj dalej)

I am assisting an elderly user with a personal @hotmail.com account that receives email successfully in Thunderbird but cannot send. I have confirmed they can send and receive emails from their online outlook.com portal. The user's computer setup is as follows:

  • Windows 11 (with latest updates).
  • Thunderbird 153.0.2 (64-bit).
  • A personal @hotmail.com account with the following server configurations:
  -> Incoming IMAP: outlook.office365.com, port 993, SSL/TLS, OAuth2, and
  -> Outgoing SMTP: smtp-mail.outlook.com, port 587, STARTTLS, OAuth2.

Thunderbird successfully authenticates to Microsoft using OAuth2 for incoming email. However, when Thunderbird attempts outgoing email authentication, Microsoft's SMTP server rejects the authentication. The Error Console in Thunderbird records this message: "535 5.7.139 Authentication unsuccessful, SmtpClientAuthentication is disabled for the Mailbox."

-> Refer to attached image: "Thunderbird Error Console_20260811.jpg". -> I am able to provide a short screen recording demonstrating the failure if needed.

To try and resolve the above, I completed the following actions:

  1. Confirmed Thunderbird is current (153.0.2).
  2. Confirmed SMTP is configured for OAuth2 rather than Normal Password.
  3. Confirmed port 587 and STARTTLS.
  4. Re-authorised the Microsoft account/OAuth connection.
  5. Confirmed IMAP OAuth2 works.
  6. Confirmed Outlook.com webmail can send successfully.
  7. Reviewed Mozilla's current “Microsoft OAuth Authentication and Thunderbird in 2026” guidance, including the section covering cases where IMAP/POP works but SMTP does not.
  8. Captured the SMTP failure in Thunderbird's Error Console.

However nothing worked, so I raised the matter with Microsoft support and eventually had the matter referred to their Tier 2 team. The Microsoft case number is: 7107041963.

Microsoft Support confirmed that for a personal Outlook.com/Hotmail account there is no user-accessible mailbox-level SMTP AUTH setting, and advised that SMTP is enabled by default for supported clients. However, because sending from Outlook.com webmail works, Microsoft Tier 2 declined to investigate the SMTP server response further and directed me to Thunderbird support.

I am able to provide a copy of the chat transcript if needed.

In any event, the TLDR version IMAP works using OAuth2, but SMTP using OAuth2 fails because Microsoft's SMTP server reports SmtpClientAuthentication is disabled for the Mailbox. Microsoft Tier 2 has referred the issue to Thunderbird support.

Questions:

  1. Is this a known current issue affecting personal Outlook.com/Hotmail accounts using Thunderbird?
  2. Is 535 5.7.139 SmtpClientAuthentication is disabled for the Mailbox known to occur with Thunderbird OAuth2 even though IMAP OAuth2 succeeds?
  3. Is there a current Thunderbird-side workaround or alternative SMTP server/configuration recommended for personal Hotmail accounts?
  4. Would changing the SMTP server from smtp-mail.outlook.com to smtp.office365.com be appropriate for a personal Hotmail account in Thunderbird 153, or should the current Microsoft-documented server be retained?

-> I note there appears to be conflicting advice on this point in previous support threads.

  1. Given that IMAP OAuth2 authentication succeeds for the same Microsoft account, does this indicate that Thunderbird's Microsoft OAuth authorisation itself is functioning correctly, or could SMTP require a separate permission/token that may be failing?
  2. Are there any additional Thunderbird logs or diagnostics I can provide that would help resolve this matter?

Disclosure: I used ChatGPT to help organise my troubleshooting notes and technical details for this post. The troubleshooting, observations and diagnostic information described above are from my own work on the affected PC.

Otwarte 3

How to filter all incoming emails to copy to another folder?

How to filter all incoming emails to copy to another folder? Filter has no "on incoming" criteria, only Subject From Date Size I want "upon arrival", copy to ... Archi… (czytaj dalej)

How to filter all incoming emails to copy to another folder?

Filter has no "on incoming" criteria, only

Subject
From
Date
Size

I want "upon arrival", copy to ... Archive will probably do.

Alternatively, is there a setting for ALL Subjects, ALL Froms, ALL Dates, ALL sizes?

Thanks.

Rozwiązane 4 100

the last days my new mails didn’t arrive

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 … (czytaj dalej)

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

Otwarte 1