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Cant send emails from outlook account in Thunderbird

  • 14 replies
  • 1 has this problem
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  • Last reply by Toad-Hall

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I have used thunderbird for years but now cant send emails from one of my outlook accounts with error Login to server smtp.office365.com with username xxxxxxx@xxxx failed. I had activity message from microsoft the other day that included something in the US so I changed my account password. Since that I keep getting the above message and it will not accept the new password. I have deleted the account and re-installed it, changed the SMTP settings and port, closed and re-opened thunderbird and re-booted the computer but cannot send a message from the account. I can still send messages from my other microsoft accounts

I have used thunderbird for years but now cant send emails from one of my outlook accounts with error Login to server smtp.office365.com with username xxxxxxx@xxxx failed. I had activity message from microsoft the other day that included something in the US so I changed my account password. Since that I keep getting the above message and it will not accept the new password. I have deleted the account and re-installed it, changed the SMTP settings and port, closed and re-opened thunderbird and re-booted the computer but cannot send a message from the account. I can still send messages from my other microsoft accounts

Modified by tonyatkinson2

Chosen solution

So this is the account that has the problem sending.

account14 (imap) imap-mail.outlook.com:993 SSL/TLS Normal password smtp.office365.com:587 STARTTLS OAuth2 true

Now we know that there is only one account /email address that is using that smtp.office365.com server name. It is the email address/mail account you removed and added again - which I'll call 'X'@live.co.uk because I do not know that specific email address - but you do.

It would be reasonable to get that smtp the same as all the other working acounts. Previously, that account was hooked up to an smtp that was already being used for another email address, so it caused a problem, but now we know it is properly set up but server settings need to be adjusted.

In 'Account Settings' In left Pane

  • Select the name of the 'X' live.co.uk email address/mail account - the one you added again - it may be at the bottom of the list.
  • Look bottom right for 'Outgoing Server (SMTP)'
  • click on 'Edit SMTP_Server' button

At the moment, it should say the following:

  • Description: email address of the 'X'@ live.co.uk account name
  • server name: smtp.office365.com
  • Port: 587
  • Connection SEcurity: STARTTLS;
  • Authentication Method: OAuth2
  • User name: full email address of 'X' @live.co.uk

Edit so you now have the following - take care - remove data from line then add carefully - no typos:

  • Description: email address of the 'X' @live.co.uk account name
  • server name: smtp-mail.outlook.com
  • Port: 587
  • Connection SEcurity: STARTTLS;
  • Authentication Method: Normal Password
  • User name: full email address of 'X' @ live.co.uk
  • click on 'OK'

Now make sure there is no currently saved password for the smtp for 'X' @ live.co.uk mail account.

  • Menu icon > Preferences (in v102 this is now 'Settings') > Privacy & Security
  • Under 'Passwords' section
  • click on 'Saved Passwords' button
  • click on 'Show Passwords' button

You should see a imap:// line for the 'X'@live.co.uk email address - do not delete it. But please note the 'password' you have got saved for that account.

You are looking for the smtp:// line and/or possible oauth:// line (but it might not be stored) for the 'User Name' that is the 'X'@live.co.uk email address.

  • If you see the smtp and/or oauth , select it and click on 'REmove'

If it does not exist - that's good.

  • click on 'Close'

Exit Thunderbird.

Now before you start up Thunderbird, you need to check that you can successfully access that account via the webmail account using a browser. So, using the 'X'@live.co.uk email address and it's password - logon to webmail account. You need to be certain that you can get access and the password works ok.

When you have access....

Start Thunderbird. Please do not attempt too send anything just yet - Wait until you have received some emails into the account called X'@live.co.uk. You can always send an email from one of your other accounts to that X'@live.co.uk email address. After you have received emails into the X'@live.co.uk mail account then try to 'Send' and it should prompt for password. Enter the same password you used to access webmail. Select the checkbox to remember password. click on OK

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All Replies (14)

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re : I had activity message from microsoft the other day

Are you certain the email was real? There have been several reports recently of these types of emails. If you hover over the 'Review recent Activity' button, it should tell you what it really links up to in the bottom 'Status bar'. If you click on the links then it might ask you to log in on a web site that looks remarkably like the real thing but isnt - then it will record (steal) your credentials.

Only ever logon to your account via the official website and not something offering a link to it in an email.

I suggest you try to logon to your webmail account via safe login and Reset the password.


Then in Thunderbird Access: Menu icon > Preferences/Settings > Privacy & Security Under 'Passwords' section click on 'Saved Passwords' Delete all the lines that are to do with that account. click on 'Close' restart Thunderbird and enter requested data at the prompt.

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Thanks for the quick reply. Hovering over the review recent activity button reveals https://account.microsoft.com/activity so with my limited knowledge this looked very real. I have since had the same email with another microsoft account of mine, with the same link. When I look at the activity I see various things (sorry I lose the plot a bit at this level as it gets beyond me) including automatic sync with a location of United States. I am in the UK so this was not one of my devices or does it refer to an action involving Microsoft or Thunderbird that IS based in the US?? Like I said, I lose the plot around the whole hosting, location etc. I went in and changed my password but I can't use it to log into the SMTP server so it wont send mail. I did the same thing with the second account and input the new password when prompted and it worked with no problem. I then went back into microsoft account and changed the password again but when trying to input into Thunderbird I get the same problem. I have deleted the account and re-added it, deleted the account closed thunderbird and re-added it, deleted the account, closed thunderbird, re-started computer and re-added it and I still get the same issue. I did notice that one account was showing the user name of the other and when I tried to change it it changed the other one as well. I think this was a server choice issue as I have now found several different SMTP servers so I changed that and still the same problem. The latest thing I have tried is deleting and re-adding by configuring manually but this does not work either. I have really enjoyed thunderbird for years but if I cant sort this out I am going to have to abandon it and use something else

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re :I did notice that one account was showing the user name of the other and when I tried to change it it changed the other one as well.

That explains the problem.

Each mail account needs to use it's own smtp server. Somehow you had account A and B using the same smtp. So when you updated eg: B it could not work because password for B canot be used with smtp username = 'A'. This type of error can occur if the accounts were not set up correctly in the first place and then you edited using the accounts 'Edit SMTP_ Server' button which you should do unless you know it really is already set up correctly.

How many outlook accounts have you got in Thunderbird ? You need to get all the various accounts using their own smtp server. So lets start by seeing what you have got listed in the 'Outgoing Server (SMTP) list. In Account Settings Left Pane - scroll to the bottom and below 'Local Folders' you will see 'Outgoing Server (SMTP)' click on 'Outgoing Server (SMTP)' to see a list on the right side. If you need help then Post an image of that list.

Select the outlook server in list. The details will display below. Click on 'Edit' to open

  • Description: enter the same email address that you see in the 'user name' below - so it is identical
  • server name: smtp.office365.com
  • Port: 587
  • Connection SEcurity: STARTTLS;
  • Authentication Method: OAuth2
  • User name: this should already be entered but it needs to be full email address of outlook account A
  • Click on 'OK'

Now do you have another smtp for outlook ? If yes, select it in list and click on 'Edit' If no, then click on 'Add'

  • Description: enter the same email address that you use in the 'user name' below
  • server name: smtp.office365.com
  • Port: 587
  • Connection SEcurity: STARTTLS;
  • Authentication Method: OAuth2
  • User name: this should be full email address of the other outlook account B
  • Click on 'OK'


Then you have to make sure each outlook account is using it's own smtp server. In left Pane Select the name of the first outlook account Look bottom right for 'Outgoing Server (SMTP)' Do NOT click on 'Edit SMTP_Server' button - leave it alone.

This is where the 'Description' field now helps you. Is the selected outlook account email address the same email address displaying in the 'Outgoing Server (SMTP)' text box ? If yes, good it is correct. If no, click on the drop down V to see other smtp options and select the one with correct email address as account.

Now repeat for the other account. Get the Outgoing server email address matching the account email address.

Close Account SEttings tab Now you need to get rid of the stored passwords.

Menu icon > Preferences (in v102 this is now 'Settings') > Privacy & Security Under 'Passwords' section click on 'Saved Passwords' Delete all the lines that are to do with outlook accounts. click on 'Close'

Exit Thunderbird wait a few moments and then restart.

You will get prompted to enter email address and password - remember to select to save password

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Many many thanks for the detailed instructions. I will be looking at this shortly but a quick question - do you have to be a paying customer of office 365 to use that server? Most of my servers are mail.outlook.com

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Just been trying it but don't know how to enter Authentication as OAuth2. The only options I have are No Authentication, Normal Password, Encrypted Password, Kerberos/GSSAPI or NTLM. Going to try with Normal Password which is what they mainly seem to be set to

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OK, I went back in and the OAuth2 options appeared. When I tried to send an email I was diverted to a window to loginmicrosoftonline etc etc that invited me to sign in to microsoft and then said I cant sign in using a private email use a school or work address. I tried using a work email address and it said it was not in their system. I now have the window stuck open with no way to sign in, move it, minimise it or close it.

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Managed to get rid of the window but cant get past this log in that won't let me log in

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OK so having now spent two full days on this I have discovered a couple of possible things. It seems possible that the unusual activity I reported as it was in US might have been Microsoft itself as I found a forum where someone had the same problem and believes Microsoft might have blocked its own IP address or similar. I have only had this problem since I received the message and reported the activity as unrecognised. Unfortunately Microsoft "help" appears to be the most useless thing on the planet and is mis-named as there isn't any help anywhere! Is the problem with smtp.office365.com because I am not subscribed to office 365? I have other email accounts that have always worked in Thunderbird (and still do) with server smtp-mail.outlook.com. but I have tried resetting this and can't get past the password. As I said, I had the same issue with another account and when I typed in the new password it worked fine on smtp-mail.outlook.com but not for this one. Is there some confusion between the email account, microsoft account etc that use the same email address? I also found a suggestion that it could be a new Microsoft security feature Authenticated smtp but I cant find this and think it might be particular to desktop Outlook as a client or Office 365 subscribers. Unfortunately it is impossible to contact Microsoft to discuss the issues that may be to do with them. As a point of interest, I have loaded Thunderbird onto another laptop and only loaded up the email account with the issues and I can't get it to work on there either (will receive but cannot send with the same error messages) It feels as if the set up is Ok but the password for the account is just not being recognised in Thunderbird. I must admit I am losing the will to live!

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re : Most of my servers are mail.outlook.com

Please post the following information: Menu icon > Help > More TRoubleshooting Information Scroll down to 'Mail and News Account' section Copy all the text in that section and then paste it into this forum question so we can see what you are currently using for all the accounts incoming and outgoing server settings.

Because you had posted this " Login to server smtp.office365.com with username xxxxxxx@xxxx failed." in the question info, I had assumed you were set up using those settings. For your email addresses - what comes after the '@' ? Is it 'outlook.com' or 'live.com' etc ?

Modified by Toad-Hall

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Sorry but just another thing, the more I keep playing with this the more emails I keep getting saying the accounts are being blocked and having to verify. The unusual activity is always United States so I hope to God it is Microsoft as I have to verify it is me! It certainly ties up with the time I have spent on it

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Hi sorry for confusion, when it stopped working I deleted it and when I re-loaded it automatically it used 365 so I had both servers. When I sent the message I quoted the last message I had that was trying to use the 365 server. Sorry I thought I should x out the email address over security concerns. The outlook accounts I am using in Thunderbird are all @live.co.uk. The info from mail and news account as follows:

ID Incoming server Outgoing servers Name Connection security Authentication method Name Connection security Authentication method Default? account2 (none) Local Folders None Normal password account4 (imap) imap.1and1.co.uk:993 SSL/TLS Normal password auth.smtp.1and1.co.uk:587 STARTTLS Normal password true account6 (imap) imap-mail.outlook.com:993 SSL/TLS Normal password smtp-mail.outlook.com:587 STARTTLS Normal password true account7 (imap) imap-mail.outlook.com:993 SSL/TLS Normal password smtp-mail.outlook.com:587 STARTTLS Normal password true account8 (imap) imap.1und1.de:993 SSL/TLS Normal password smtp.1und1.de:465 SSL/TLS Normal password true account9 (imap) imap.ionos.co.uk:993 SSL/TLS Normal password smtp.ionos.co.uk:587 STARTTLS Normal password true account14 (imap) imap-mail.outlook.com:993 SSL/TLS Normal password smtp.office365.com:587 STARTTLS OAuth2 true

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Chosen Solution

So this is the account that has the problem sending.

account14 (imap) imap-mail.outlook.com:993 SSL/TLS Normal password smtp.office365.com:587 STARTTLS OAuth2 true

Now we know that there is only one account /email address that is using that smtp.office365.com server name. It is the email address/mail account you removed and added again - which I'll call 'X'@live.co.uk because I do not know that specific email address - but you do.

It would be reasonable to get that smtp the same as all the other working acounts. Previously, that account was hooked up to an smtp that was already being used for another email address, so it caused a problem, but now we know it is properly set up but server settings need to be adjusted.

In 'Account Settings' In left Pane

  • Select the name of the 'X' live.co.uk email address/mail account - the one you added again - it may be at the bottom of the list.
  • Look bottom right for 'Outgoing Server (SMTP)'
  • click on 'Edit SMTP_Server' button

At the moment, it should say the following:

  • Description: email address of the 'X'@ live.co.uk account name
  • server name: smtp.office365.com
  • Port: 587
  • Connection SEcurity: STARTTLS;
  • Authentication Method: OAuth2
  • User name: full email address of 'X' @live.co.uk

Edit so you now have the following - take care - remove data from line then add carefully - no typos:

  • Description: email address of the 'X' @live.co.uk account name
  • server name: smtp-mail.outlook.com
  • Port: 587
  • Connection SEcurity: STARTTLS;
  • Authentication Method: Normal Password
  • User name: full email address of 'X' @ live.co.uk
  • click on 'OK'

Now make sure there is no currently saved password for the smtp for 'X' @ live.co.uk mail account.

  • Menu icon > Preferences (in v102 this is now 'Settings') > Privacy & Security
  • Under 'Passwords' section
  • click on 'Saved Passwords' button
  • click on 'Show Passwords' button

You should see a imap:// line for the 'X'@live.co.uk email address - do not delete it. But please note the 'password' you have got saved for that account.

You are looking for the smtp:// line and/or possible oauth:// line (but it might not be stored) for the 'User Name' that is the 'X'@live.co.uk email address.

  • If you see the smtp and/or oauth , select it and click on 'REmove'

If it does not exist - that's good.

  • click on 'Close'

Exit Thunderbird.

Now before you start up Thunderbird, you need to check that you can successfully access that account via the webmail account using a browser. So, using the 'X'@live.co.uk email address and it's password - logon to webmail account. You need to be certain that you can get access and the password works ok.

When you have access....

Start Thunderbird. Please do not attempt too send anything just yet - Wait until you have received some emails into the account called X'@live.co.uk. You can always send an email from one of your other accounts to that X'@live.co.uk email address. After you have received emails into the X'@live.co.uk mail account then try to 'Send' and it should prompt for password. Enter the same password you used to access webmail. Select the checkbox to remember password. click on OK

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Dear Toad-Hall, Many many thanks for your excellent service, prompt replies, detailed instructions and most of all patience! I followed your latest instructions and it seems to have cracked it as I have sent emails from that account to 3 other accounts with no problem. Obviously got some confusions in there that I needed someone with expertise to identify. Thanks again for the excellent assistance, pity we can't forward this to Microsoft to show them what customer service should look like.

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Good to hear all is now sorted and everything working as expected. All the best :)