Suggestion: if you think you have problems with your SMTP setup, then you need to share that information before anyone can offer suggestions. Sending screenshots is the preferred approach to ensure all settings are shown. Writing in ALL CAPS is not appreciated.

In https://support.mozilla.org/en-US/questions/1462756 the user posted

       DESCRIPTION SERVER NAME
        PORT 587-DEFAULT 587
        SECURITY AND AUTHENTIFICATION
        CONNECTING SECURITY THIS IS WHAT I PUT STARTTLS
        AUTHENTIFICATION METHOD: NORMAL PASSWORD

See https://support.mozilla.org/en-US/questions/1461241 https://support.mozilla.org/en-US/questions/1409482 https://support.mozilla.org/en-US/questions/1444249

There is also an article on https://support.mozilla.org/en-US/kb/thunderbird-and-yahoo but perhaps it needs an update?

re :Now I cannot received or send any outgoing mail!

So you have a problem with more than just sending.

Do the following to ensure settings are ready for any alterations.

1. Make sure Firewall has Thunderbird program as an allowed program.

• Exit Thunderbird
• Access Firewall - this may be the default one on computer OR it may be controlled by whatever Anti-Virus software you have installed.
• Set up Thunderbird as an allowed program to ensure the Firewall is not blocking any access.

Provide info:

• Confirm you have Thunderbird set up as an allowed program
• Tell us what Anti-virus you are using.

2. Set up to allow cookies. In Thunderbird

• Settings > Privacy & Security
• Under 'Web Content'
• Select checkbox : 'Accept cookies from sites'
• Accept third party cookies 'Always'

Provide info:

• Confirm you have set up to allow cookies.

3. Post this info:

• In Thunderbird
• Help > Troubleshooting Information
• Scroll down to 'Mail and News Accounts' section
• Copy all the data and paste it into this forum question.

It's possible you are not set up to use 'Authentication Method: Oauth2' for receiving or sending, but you need to post that info so we can advise.

Mr. Mery, this does not solve my problem, let me be more specific, the issue that I'm having only has to do with outgoing mail, I receiving incoming mail, the illustration box I typed out is what I'm having issues with, I do not know where to put the correct info for outgoing mail. I have a question, there is a support phone number that I came across that is (817) 406-3036, is this a legitimate phone number are is this a fraudulent phone number, I need personal technical assisitance!

                                                                            Thank You,
                                                                             D.S.
                                                                             willowby4@yahoo.com

Mr. Mery, this does not solve my problem, let me be more specific, the issue that I'm having only has to do with outgoing mail, I receiving incoming mail, the illustration box I typed out is what I'm having issues with, I do not know where to put the correct info for outgoing mail. I have a question, there is a support phone number that I came across that is (817) 406-3036, is this a legitimate phone number are is this a fraudulent phone number, I need personal technical assisitance!

You can pay any who has the correct credentials to sort out your issues. That is your choice. Thunderbird does not have a Support telephone number. Thunderbird is a free program and relies upon donations to maintain the program. It does not have income like Microsoft and therefore does not have rooms full of people answering phones in various countries around the world.

Sorry you posted a question stating and I quote "CANNOT RECEIVE OR SEND" Then you said you can receive but not send. But the lat image you posted says you can send but email was not saved in Sent folder.

You seem to have a constant changing of your issue.

re :the illustration box I typed out is what I'm having issues with The info you typed has errors and they maybe typo errors because the server name does not match the one displayed in the error message. You have also posted two different error messages.

It is possible you have not set up Thunderbird to use Oauth. You may have used information provided by Wayne to alter the smtp server to use Authenication Method Oauth, but you would need the incoming to be the same.

Either way - we do not know exactly what is set up.

We do not know what Anti-Virus you use and that could be causing a problem such as still scanning emails you sent or files that get opened so data cannot get written to file etc etc.

So please read my previous comment and respond back with all the required information. Then we can check everything is set up correctly.

Sorry for the confusion, I can receive incoming emails but cannot send out outgoing emails. The info I sent you about the server for outgoing mail is where the issue is, and I do have auth 2 setup, and that did not help. Let me be more sdpecific where it says accounts and smtp server, settings and description I enter my email address,under server name i put smtp.mail.yahoo.com,port is 587, default 587, security and authtification, connection security is STARTTLS, these are caps, authentification method says normal password, user name is my email address willowby4@yahoo.com, then I click ok, I must have something wrong in this server box! If Mozilla Thunderbird expects donations, which I would be more than happy to donate, I need some support on how to fix issues.

                                                                            Thank You For Your Time,
                                                                             D.S.
                                                                             willowby4@yahoo.com

You need to set authentication to oauth, and only oauth, as Toad-Hall has suggested and as documented at https://support.mozilla.org/en-US/kb/thunderbird-and-yahoo. And not have cookies and javascript disabled.

I have a question, there is a support phone number that I came across that is (817) 406-3036, is this a legitimate phone number are is this a fraudulent phone number, I need personal technical assisitance!

There is no direct support by phone, chat or email for any free to download and use Mozilla related products. That fake phone support number comes up for a wide range of fake product and email service support in a search engine search results.

https://support.mozilla.org/en-US/kb/avoid-and-report-mozilla-tech-support-scams

Mozilla does not provide telephone support, does not charge for downloads, upgrades or technical support and does not endorse any company that does. Companies that ask for payment or personal information for installing, updating or providing support for Firefox or Thunderbird are not affiliated with Mozilla and should be avoided.

Mozilla does have direct ticket support for a few of their products that are subscription based like Mozilla VPN, Mozilla Monitor Plus, Firefox Relay premium, MDN Plus because you paid for it as part of the monthly or yearly subscription.

I paid a a vey hinest computer tech to fix the issue and to tell you the truth, this was a very complicated issue involving Yahoo, finally I can send out outgoing mail now thanks to this great tech.

re : I do have auth 2 setup, and that did not help. Let me be more sdpecific where it says accounts and smtp server, settings and description I enter my email address,under server name i put smtp.mail.yahoo.com,port is 587, default 587, security and authtification, connection security is STARTTLS, these are caps, authentification method says normal password,

When people ask for information it is for a very good reason. I'm not asking for the goodness of my health. The intention is to offer you specific instructions on ensuring you have everything set up correctly.

First you say and I quote "I do have auth 2 setup" Then you say and I quote "authentification method says normal password" So from that statement, I can assume you do not seem understand what is meant by 'Oauth2'. It means for the yahoo account, you need both incoming server settings and outgoing smtp server settings, to use the following: 'Authentication Method: Oauth2'

In order for that to work you must have cookies enabled in Thunderbird.

I do not know if you have set up the correct settings even at this point because you are still not posting the required information.

As you kept changing the problem initially reported you could have had several things not set up correctly. My intention was to ensure everything was correct.

As a heads up, it's not complicated. You post the requested information. Then you get specific tailored advise on what to do.

We had already posted some information that would have sorted you out, but it was clear you were a novice and needed a more tailored and personal approach. Hence needing the requested information.

In future, if you need help on any aspect of Thunderbird, please co-operate and provide the specific information that is requested, so that instead of going backwards and forwards with no progress, a solution can be provided in the correct manner and in terms that you would understand.