Each and every one of your account has to have their own SMTP server setup. The screen you are looking at is where you create and edit SMTP server setups.

There is another field on the main Server Settings page that also says Outgoing Server (SMTP). This is where you assign the SMTP setting you created to individual accounts. You seem to have a SMTP setup assigned to the problem account that belongs to a different address. See image.

Thank you for showing me the other Outgoing Server (SMTP) at the bottom of the left column. But I still don't understand.

I have three accounts. Account 1 is 'smtp.googlemail.com (Default). Account 2 is 'smtp.gmail.com'. Account 3 is 'smtp. googlemail.com'. I matched these up with the Outgoing Server on the Account Name page.

I didn't 'create' any settings, that's what came on Thunderbird. I don't understand 'create' here. I've tried editing them, i.e. changing googlemail to gmail for one or two, because that's all I know about editing or creating. One of the results was 'please enter new password' and wouldn't send. So the problem worsened.

Can you help, please? in simple language? Thanks in advance.

No account settings come on Thunderbird. If you did not create them someone did.

I just remember when adding an account to Thunderbird that everything came in automatically.

How do you create account settings?

Post your troubleshooting information. Go to the Thunderbird Help menu and select Troubleshooting Information. Click copy to Clipboard. Come back here and paste that info in a reply window.

I clicked 'Copy text to Clipboard' and nothing happened.

Paste what info?

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Okay you have 3 different gmail accounts listed. Each one of those needs a SMTP server setup that references it's username. Go to the screen I showed in the image that references "create or Edit" and make sure you have a SMTP server for each username you have. If not fix that. Then go to the other place shown in the image and match the correct server with the correct account.

The only field in the SMTP setup that has to be different is the username. Ideally you name each one something that means something so you can tell them apart and match them to the correct account.

For example, if you have bob@gmail.com, billybob@gmail.com and suebob@gmail.com you will have 3 distinct SMTP servers setups with those as the username. Then match the SMTP server with the corresponding account.

Thank you.

"If not fix that." How do I fix that?

Do you mean instead of 'smtp.gmail.com' or 'smtp.googlemail.com' I could put 'smtp.tonymail.com' for example?

No, no, no!

They are the names (strictly speaking, addresses) of an email server. Change those and Thunderbird won't be able to find the server. In practice, your three gmail accounts could use exactly the same address. It's the username (i.e. your email address) that differentiates between them.

What you need to edit are the descriptions.

Go to Tools|Account Settings. Go down to "Outgoing Server (SMTP)".

Select each of your gmail smtp settings in turn. In each one, you'll see the user name (email address) it works with. As said, you need one of these smtp settings for each of the gmail accounts. Edit the "description" to say something that tells you which account it belongs to. The smtp account's email address, mentioned in the smtp settings page would be helpful, but if you have any other personal way of identifying these accounts, (e.g. "tonymail") then fine, use that. The description is for YOUR use and benefit. Everything else in there is dictated by what the server needs to be told, so has to comply with whatever the email provider (in this case, googlemail) uses.

Now you can go back to the Incoming account settings and in each, select its corresponding smtp server.

"Now you can go back to the Incoming account settings..."

This is the first time I've heard 'incoming account settings'. I don't know how to go to that. Can you help me please?

I gave you an image days ago showing the 2 different locations. Maybe you need to find some local help.

Thank you for your assistance.

I can't see where you mentioned 'incoming account settings' before.

I can't see 'incoming account' on the image you sent me.

I would appreciate your clarification, thanks in advance.

One area pointed out in the image says create and edit here. The other area says ASSIGN to accounts here. Assuming you actually created a SMTP setup for each of your gmail accounts you go to the ASSIGN area and assign them to the account they go with.

As I said before, I didn't 'create' any smtp setup, and I don't know how to 'create'. There is 'add' on the main 'Outgoing Server' image attached. Is that it? Well, I don't need to 'add' any more email addresses, if that's what 'create' means.

You can see on the attached images that I've ASSIGNED according to the accounts they go with.

A while ago, one of the servers was named 'smtp.googlemail.com' and the others 'smtp.gmail.com' and I changed them around a bit but it didn't seem to make any difference so I made them all 'smtp.gmail.com'.

I'm still with the same problem. When I send an email from tppublications@gmail.com it gets received as from tplanguageassessment@gmail.com.

Any other suggestions or corrections?

make them all oAuth as well.

Did that. Problem persists.

I have to ask.

When you click reply, does the correct address show at the top of the reply windows (before you click send)

I don't think there's anything to do with replying.

I send an email from tppublications. The recipient gets it from tplanguageassessment (and is confused). Looking in the 'sent' folder of tppublications, it tells me the message has been sent from tppublications. But it hasn't really. Because looking in the 'sent' folder of tplanguageassessment, the message has (also) gone from tplanguageassessment, and it has really.

The antopenston address works ok.

Go to each account's incoming settings. Just as Airmail advised here: https://support.mozilla.org/en-US/questions/1226136#answer-1134064

Make sure each one has the relevant smtp server setting associated with it.

I did advise you to rename these smtp servers. Since you haven't followed this advice, you'll have to work out which of Google Mail 1, Google Mail 2 and Google Mail 3 is the right one for each of your accounts.

It would be so much easier if you changed these descriptions to include the account names.