Thunderbird can receive but not send email via smtp-mail.outlook.com

Question

Thunderbird can receive but not send email via smtp-mail.outlook.com

Anonymous 5

I recently created a NEW PERSONAL ACCOUNT in OUTLOOK.ES.

The rest of the accounts are working correctly, but with this last one I'm unable to send emails from Thunderbird, returning ...

"Login to server smtp-mail.outlookoom with username [PII]

Followed by

"Sending of the message failed. Unable to authenticate to Outgoing server (SMTP) smtp-mail.outlook.com. Please check the password and verify the 'Authentication method' in 'Account Settings | Outgoing server (SMTP)'."

Receiving mail works fine. Sending mail on other accounts (both smtp-mail.outlook and smtp.office365) works fine.

Have tried IMAP and POP3 with the same result.

Regarding console, I get the following message ...

Command failed: 535 Authentication unsuccessful, SmtpClientAuthentication is disabled for the Mailbox.

Error during AUTH XOAUTH2, sending empty response.

Command failed: 500 Unrecognized command 'Length: 7'.

Please advise.

Thank you!

PS. I've also updated Thunderbird to the latest version and verified Telnet access to smtp-mail.outlook and smtp.office365.

Mohamed Saleh 5 Reputation points

2026-08-02T10:10:12.8+00:00

Is there any news about fixing this issue the sending is working from the outlook.com and only in mail clients now working i tries thunderbird and mailspring both seems to read the mail but not sending mail. and this only for my newly created account. but for the old one it works just fine
the error seems to be related to SMTP is diabled for my account although i alreaady enabled it in the mail settings with imap and still now working it there any fix for this ?
Anonymous 5 Reputation points

2026-08-02T14:18:38.1366667+00:00

All the indicated steps had already been tested during the previous three, hence the opening of the case.

Outlook.com webmail worked correctly the entire time.

Fortunately, today, four days after creating the account, it has started to function correctly.

I would recommend that if this is a common error in newly created accounts, customers be notified in advance.

In any case, I appreciate your help and wish @Mohamed Saleh the same success.
Anonymous 5 Reputation points

2026-08-02T14:19:21.4133333+00:00

The problem is happening again ...
Matthew Kowalski 0 Reputation points

2026-08-04T13:48:07.5066667+00:00

I have been having the exact same issue with my hotmail account that I created in mid-June. After a long time with various Microsoft support personnel two weeks ago, I eventually got the following response:

"I would like to inform you that SMTP/POP configuration will not work for newly created accounts in that case."

When I asked if there was any documentation about this policy (which I could not find online), I received the response:

"Based on the information available to me, I am not aware of a published Microsoft policy that permanently blocks SMTP OAuth2 for all newly created Outlook.com/Hotmail accounts"

I then asked if there was any information about how long this restriction would last on newly created accounts and received the response:

"I suggest you to wait for a few more days or weeks and try again. The restriction is for newly created accounts only for a certain period of time."

Now, these responses were not super helpful, so the situation is still unclear. Regardless, it appears that newly created accounts do not have SMTP authentication enabled, despite the fact that I can't find any documentation from Microsoft about this.
Ian-T 7,850 Reputation points Microsoft External Staff Moderator

2026-08-05T08:34:41.6133333+00:00

Hi everyone,

This appears to be an account-side SMTP issue affecting some newly created personal Outlook.com accounts, not simply incorrect Thunderbird settings. Thunderbird should use smtp-mail.outlook.com, port 587, STARTTLS, and OAuth2

Since the issue may return even after working temporarily, waiting is not a confirmed fix. For now, use Outlook.com or the Outlook app to send mail and report the issue through Outlook.com support. Community moderators cannot enable SMTP or change the mailbox from the forum side.

Please feel free to also contact Microsoft Support for further assistance as well. Thank you for your understanding
Mohamed Saleh 5 Reputation points

2026-08-05T08:48:22.6766667+00:00

@Ian-T
Hello Ian can you please provie a link to which support i can send email or chat to ? i made sure my mail client is using the correct settings. but still not working
Ian-T 7,850 Reputation points Microsoft External Staff Moderator

2026-08-05T09:39:44.3333333+00:00

Hi

Please go to https://support.microsoft.com/en-us/home/contact?SourceApp=smc2&ContactUsExperienceEntryPointAssetId=S.HP.SmcContactUsLanding and type in "Live chat" - click Get Help - scroll down and click Contact Support.
Then choose Microsoft 365 and Office as Products and services, Category as Technical Support.
You will be prompted to get a live chat session with an support agent.

Thank you
Anonymous 5 Reputation points

2026-08-08T08:21:31.6033333+00:00
Matthew Kowalski 0 Reputation points

2026-08-08T21:47:10.12+00:00

That is essentially the same response that I received from support.

2 answers

Your answer

Mohamed Saleh 5 Reputation points

2026-08-02T10:10:12.8+00:00

Is there any news about fixing this issue the sending is working from the outlook.com and only in mail clients now working i tries thunderbird and mailspring both seems to read the mail but not sending mail. and this only for my newly created account. but for the old one it works just fine
the error seems to be related to SMTP is diabled for my account although i alreaady enabled it in the mail settings with imap and still now working it there any fix for this ?
Anonymous 5 Reputation points

2026-08-02T14:18:38.1366667+00:00

All the indicated steps had already been tested during the previous three, hence the opening of the case.

Outlook.com webmail worked correctly the entire time.

Fortunately, today, four days after creating the account, it has started to function correctly.

I would recommend that if this is a common error in newly created accounts, customers be notified in advance.

In any case, I appreciate your help and wish @Mohamed Saleh the same success.
Anonymous 5 Reputation points

2026-08-02T14:19:21.4133333+00:00

The problem is happening again ...
Matthew Kowalski 0 Reputation points

2026-08-04T13:48:07.5066667+00:00

I have been having the exact same issue with my hotmail account that I created in mid-June. After a long time with various Microsoft support personnel two weeks ago, I eventually got the following response:

"I would like to inform you that SMTP/POP configuration will not work for newly created accounts in that case."

When I asked if there was any documentation about this policy (which I could not find online), I received the response:

"Based on the information available to me, I am not aware of a published Microsoft policy that permanently blocks SMTP OAuth2 for all newly created Outlook.com/Hotmail accounts"

I then asked if there was any information about how long this restriction would last on newly created accounts and received the response:

"I suggest you to wait for a few more days or weeks and try again. The restriction is for newly created accounts only for a certain period of time."

Now, these responses were not super helpful, so the situation is still unclear. Regardless, it appears that newly created accounts do not have SMTP authentication enabled, despite the fact that I can't find any documentation from Microsoft about this.
Ian-T 7,850 Reputation points Microsoft External Staff Moderator

2026-08-05T08:34:41.6133333+00:00

Hi everyone,

This appears to be an account-side SMTP issue affecting some newly created personal Outlook.com accounts, not simply incorrect Thunderbird settings. Thunderbird should use smtp-mail.outlook.com, port 587, STARTTLS, and OAuth2

Since the issue may return even after working temporarily, waiting is not a confirmed fix. For now, use Outlook.com or the Outlook app to send mail and report the issue through Outlook.com support. Community moderators cannot enable SMTP or change the mailbox from the forum side.

Please feel free to also contact Microsoft Support for further assistance as well. Thank you for your understanding
Mohamed Saleh 5 Reputation points

2026-08-05T08:48:22.6766667+00:00

@Ian-T
Hello Ian can you please provie a link to which support i can send email or chat to ? i made sure my mail client is using the correct settings. but still not working
Ian-T 7,850 Reputation points Microsoft External Staff Moderator

2026-08-05T09:39:44.3333333+00:00

Hi

Please go to https://support.microsoft.com/en-us/home/contact?SourceApp=smc2&ContactUsExperienceEntryPointAssetId=S.HP.SmcContactUsLanding and type in "Live chat" - click Get Help - scroll down and click Contact Support.
Then choose Microsoft 365 and Office as Products and services, Category as Technical Support.
You will be prompted to get a live chat session with an support agent.

Thank you
Anonymous 5 Reputation points

2026-08-08T08:21:31.6033333+00:00
Matthew Kowalski 0 Reputation points

2026-08-08T21:47:10.12+00:00

That is essentially the same response that I received from support.

Answer 1

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Answer 2

Please note that this is a public forum. We will edit your question to hide personal information, but please avoid sharing personal or organizational details in future posts to protect your privacy.

Hi Forum

Please reply with only these details:

Whether sending works from Outlook.com.
Whether Thunderbird shows OAuth2 for the outgoing SMTP server.
Whether the account is an @outlook.com, @hotmail.com, @live.com, or @outlook.es address.
A screenshot of the Thunderbird SMTP settings with the email address hidden.

Please try the steps below:

1) Enable IMAP access in Outlook.com on the web

Sign in to Outlook.com, then go to Settings > Mail > Forwarding and IMAP. Under POP and IMAP, turn on Let devices and apps use IMAP, then select Save.

2) Use the official Outlook.com SMTP settings in Thunderbird

In Thunderbird, go to Account Settings > Outgoing Server (SMTP), then edit the SMTP entry for this Outlook.com account only.

Use these settings:

Server name: smtp-mail.outlook.com
Port: 587
Connection security: STARTTLS
Authentication method: OAuth2
User name: your full Outlook.com email address

3) Make sure Thunderbird is not reusing another account’s SMTP server

In Thunderbird, go to Account Settings > select the affected Outlook.com account > Outgoing Server (SMTP). Select the SMTP server that belongs to this exact Outlook.com address.

Do not reuse the SMTP entry from another Outlook.com, Microsoft 365, or Gmail account.

4) Remove the saved Thunderbird sign-in token for this account

In Thunderbird, go to Settings > Privacy & Security > Saved Passwords.

Remove saved entries related to:

The affected Outlook.com address
smtp-mail.outlook.com
outlook.office365.com
Microsoft sign-in or OAuth entries

Then restart Thunderbird and try sending again. Thunderbird should open a fresh Microsoft sign-in window.

5) If OAuth2 is not available, recreate the SMTP entry

Delete only the outgoing SMTP entry for the affected account, then create it again using the settings in step 2.

After saving it, reopen the SMTP entry and check whether OAuth2 appears as an authentication option.

6) Try removing and re-adding the account in Thunderbird if the issue continues

If the settings look correct but sending still fails, remove the Outlook.com account from Thunderbird and add it again.

7) Test sending directly from Outlook.com webmail

Please test sending from Outlook.com.

If sending works on the web but not in Thunderbird, the issue is likely limited to Thunderbird’s SMTP/OAuth setup.
If sending also fails on the web, the Outlook.com account itself may need Microsoft account support review.

8) Use Outlook.com web or the Outlook app as a temporary workaround

Until SMTP authentication works in Thunderbird, you can send mail from Outlook.com or from the Microsoft Outlook app.

Please tell me how it goes. If the problem persists, please don’t hesitate to reply to this thread and I will be happy to help. Have a lovely day!

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