Please post account settings and ISP, e.g., POP or IMAP, server settings in and out. And, what did you mean by 'one of the different address that are defined...'?

Thanks for your reply.

My wife and I are sharing this computer and so we also share Thunderbird for all our e-mail accounts (I have 4, my wife 2). So we have in total 6 entries in the SMTP section.

Inbound most accounts are POP, only my gmail account is IMAP. ISPs are strato.de (2x), yahoo.de, ionos.de, arcor.de and gmail.com. All server settings have SSL/TLS, gmail and yahoo require oauth2, the others password.

Outbound we use the same security settings for SMTP.

That's all working fine since years. If I get an e-mail and I click on respond it will be sent from the same e-mail address it was originally sent to.

Only if it was not sent directly to my wife, but she was part of a group of BCC recepients: when she tries to respond it will be sent with my (!) e-mail address. Unless she looks at the sender line by chance... Then she can change it to her address by using the drop-down menu of possible sender options. Theses 2 accounts in question are both hosted by strato.de, so the server setting is SMTP.strato.de.

That's not an the-end-of-the-world kind of problem, but it is annoying, because it does confuse the recepients from time to time if an e-mail is coming from me but written by her... And then they respond to me etc...

Regards, Dieter

Check to see what SMTP each of you are using. She needs to be using a separate SMTP than you are using. Look explicitly at tools>account settings >account>Outgoing server setting for each account. Also, scroll down left pane to Outgoing Server (SMTP) and you see six smtp servers, all unique. The setting for your wife's should be her email id. Please check all that and let us know.

As I said, there are 6 different unique smtp servers in that list. The one of my wife is the one that is printed bold and has (Standard) in brackets at the end which means default in English.

That is the server / address she always has in the sender line if she creates an e-mail or if she responds to an incoming e-mail. Only if she is recepient of a undisclosed recepients group Thunderbird has my address as sender.

It may help if you post screen shots of tools>account settings>account for both your and her accounts. I respect what you're saying, but sometimes having other eyes viewing the account settings proves helpful.

Sure :-) Making the screen shots I saw that the settings are not that identical as I thought...

There are some real e-mail addresses on the screen shots that I didn't want to have in the internet, so I tried to partially hide them. Hope you can still see enough...

re :That is the server / address she always has in the sender line if she creates an e-mail or if she responds to an incoming e-mail.

If the email has been received directly into your wifes strato.de email address mail account and your wife is currently viewing that account, a Reply or new Write message should auto use the strato.de email address of same account in the 'FROM' field and also use the SMTP strato.de server settings where the username = same email address.

However, what is written in the 'FROM' when sending an email does not mean it is sending using that 'FROM' email address. Hence why you would verify that in the Account Settings. You mention you have two ISPs are strato.de (2x), so I'm presuming there are two email addresses; one for wife and one for you.

If Thunderbird is having an issue knowing what the correct FROM should be then by default it will use the account set up as default. The default account is usually the account listed at the top of the Folder Pane and also in the Account Settings window. That same account email address/user name is usually set up as the default smtp.

So first we need to verify a couple of points. Please help us to help you by providing some info:

1. Is your wife's strato.de mail account displayed at the top of the Folder Pane and at the top of the list in the 'Account Settings' window ? OR is it your strato.de email address at the top ?

2. Are all of your POP mail accounts displayed separately in the Folder Pane and each email address has it's own set of folders ?

We need to be absolutely certain that this is set up correctly and cannot assume it is correct just because the 'FROM' has correct email address on certain occasions. We cannot see it and rely upon you to show us. Please go through this process.

• Right click on wife strato.de email address mail account name in Folder Pane and select 'Settings'
• bottom RIGHT- Outgoing Server SMTP - click on 'Edit SMTP_Server' button

Does the 'User Name' = same email address as the mail account you are viewing = your wifes email address for strato.de? If it is different then do NOT edit via that access or else you may end up editing something which is pointing to another strato.de email address. Please Report back letting us know if that username = wife email address on strato.de OR whether the username was actually the other strato.de email address.

• In 'Account Settings' window - Look in the LEFT Pane
• Go to the bottom and click on 'Outgoing Server (SMTP)'

It will list all your smtp servers.

You say your wife's strato.de email address account is using the Outgoing Server that says it is 'Default' - "The one of my wife is the one that is printed bold and has (Standard) in brackets at the end which means default in English."

• Select the smtp in list which says it is (Default).
• Is the 'User Name' the same email address as your wife's strato.de email address ?

If no, then your wife's email address mail account is not using the correct outgoing server smtp.

Select the other strato.de smtp in list - does it have User Name = wife's strato.de email address ? If yes, click on 'Edit' and in the 'DEscription' field type: Wife Strato click on 'OK'

In LEFT Pane - Reselect the mail account for wife strato email address. Bottom RIGHT - Outgoing Server SMTP - click on the Drop Down to see list ad select the one that says 'Wife Strato' Then restart Thunderbird to ensure account has been properly reset.

Please report back on your findings. Images will help.

I added last comment before I saw your posting.

I can see that the default mail account is your mail account, but the default smtp is your wifes email address.

So, this would explain why your email address is inserted into the 'From' when TB is uncertain what to use. It would be useful to know what is in the source of the email. select email, click on 'More' and select 'View Source'

What is in the 'X-Account-Key'? What is in the TO field?

The pictures above do answer some of your questions regarding the SMTP settings. Yes, my wife's (Birgit) email address is the one that is default in the SMTP setting.

But, to be honest, her account is the only one that is not using an own folder for incoming emails. Her incoming mails are going to some local folders following some filter rules. To change that and try again will take some days, because there are some thousands of emails ("don't blame me" ;-) to move to the new structure. She does not like archive folders...

I will report back when I have tried again...

Thanks so far and best regards, Dieter

Oops, "I added last comment before I saw your posting." Same for me...

I cannot follow up today, will post the information tomorrow morning.

Thank you

What is in the 'X-Account-Key'? What is in the TO field?

X-Account-Key: account5 X-Envelope-To: <Birgit@f******-****a.de> To: =?iso-8859-1?Q?I***_********d_=3A=3A_CZF?=

Real addresses masked... What's in the TO field is the alias you see in Thunderbird for the group of BCC recepients.

Thanks for info.... re: her account is the only one that is not using an own folder for incoming emails. Her incoming mails are going to some local folders following some filter rules.

Please clarify - Do you mean: 1. Her POP account mail account name does NOT display in the Folder Pane - it does NOT have it's own set of folders. Instead, it is set up as a deferred account more commonly known as 'Global Inbox' and therefore all emails are automatically coming into the 'Local Folders' mail account ?

OR 2. do you mean that POP account name does display in the Folder Pane and the pop account has it's own set of folders. Then Message Filters move selected incoming mail from X sender where she is Bcc'd into another folder in the same POP account.

OR 3. do you mean that POP account name does display in the Folder Pane and the pop account has it's own set of folders. Then Message Filters move selected incoming mail from X sender where she is Bcc'd into another folder in the 'Local Folders' mail account.

Thanks for your reply.

I meant 1. This is the only account not having an own entry in the folder pane but instead her emails are coming automatically into local folders.

Usually, the info in the TO field is then used in the 'FROM' when sending a reply. I believe this has to do with the TO field not being able to be recognised as one of the mail accounts in Thunderbird and therefore is defaulting to use the mail account set up as default in the FROM field - which is your mail account listed at the top as it is set up as the default mail account.

Please try this:

• Right click on default mail account - the one at the top of the Folder Pane which is your strato.de account and select 'Settings'
• Bottom right - click on 'Manage Identities' button
• click on 'Add'
• Now enter all the details for your wifes strato.de email address.
• Remember to scroll down and enter the wife email address smtp default server because it needs to be sent via the correct smtp server.
• Then select 'Copies & Folders' tab and enter all the details of her account, so any sent emails etc get put into the correct account.
• Once all the settings are correct, click on OK

You have added your wifes email address as an identity in your own mail account. Make sure your identity is still the default.

then select that Bcc'd email and click on 'Reply' - what happens in the 'Write' window? If this does not work, you can easily remove that newly added identity.

RE: X-Account-Key: account5 What mail account is assigned to 'Account5'

• Menu app icon > Help > More Troubleshooting Information
• Select the checkbox 'Include Account'
• Then scroll down to 'Mail and New Accounts' section

ID column tells you the account number. Q: Is 'account5' your wife's strato.de email address  ?

Then scrollback up and uncheck the 'Include account' before closing tab.