There is no bug. you need to change your settings. If you want an account to have multiple identities, then you need to create additional entities for the account. Once done, Thunderbird will honor the identities. And, the from will ALWAYS be from the account's default unless the user specifies alternatives.

For anyone requiring on how to do this:

• In Account Settings
• In left pane - Select name of account
• bottom right click on 'Manage Identities' button
• You can add the various email alias's addesses and set up some settings preferences.

David - Todd - I do am NOT talking about identities. Aliases and identities are different things. Thanks for the reply

No, what I proposed WORKS. I agree that identities are not necessarily aliases, but if you use aliases you need to use identities.

David - Todd - I do am NOT talking about identities. Aliases and identities are different things. Thanks for the reply

In this instance, 'identities' are various email addresses commonly created as 'alias' email addresses in webmail accounts. If you have those email addresses being collected into a main account, then setting each 'alias' email address as an 'identity' in the account will faciliate sending using the email address.

The alternative is to set up those different alias email addresses as mail accounts in Thunderbird where they appear as a separate mail account in Folder Pane with their own set of folders Then any emails sent to that email address will end up in their own mail account, so a reply would auto use that email address as the From.

Hi, thank you for your reply and I hope this does not sound rude but you are missing the whole point of aliases. Aliases, unlike identities, are zero setup. Whenever you send email you just add a hyphen and a made up alias to the first part of your email address. That way you can have completely separate email addresses for whoever you send them to. If you first have to create and identity, then what is the point of having aliases?

And again, the developers understand that which is why in the new message window the dropdown menu under "from" shows "customize from address.." This is where the alias gets typed. Zero setup. It is perfect, except replying defaults to the main (unaliased) email address, which is the whole topic of this post.

And honestly, I do not see how it ever can be useful to not reply from the same email address (alias) that and email was sent to. If I give someone an email address (or aliased email address) to email me at, I ALWAYS want to reply to them with the same email address. This is why I call it a bug. This app is close to perfection, if it only would always put the correct from address, the address the mail I am replying to was sent to, in the from field. I appreciate your time responding but somehow I do not feel that the relevancy of this issue is being recognised. thank you

Hi. Since this did not get resolved or acknowledged, can anyone please direct me to the support for Thunderbird? Is there a next level? I don't mind paying. Thanks

This is Thunderbird support. You have received good information from people who know what they are talking about. Thunderbird may not work as you wish that it would.  :(

There is a place to suggest feature changes. It may be here:

https://connect.mozilla.org/

Hi. Can you please explain why you do not think it's a bug that a reply would not always originate from the address it was sent to? I am a reasonable person and I want to understand. Thanks

A bug is an error in programming, as you must know. I believe that Thunderbird is working as intended. It does indeed reply from the alias/identity to which a message was sent as long as that alias/identity is set up in Thunderbird (and probably set up at the e-mail service provider too, which is what I do). What you want to do with a customized "from" address has just not been programmed.

The message that appears when one starts to use a customized "from" address says that this function is a "one-off". I had not used this function until I tested it just now and I do not know more about it. But I don't see a programming error. The function does work as a "one-off". What I see is that you would like a feature that has not been programmed.

Ok. I still don't see why it is better not to always reply from the address the mail was sent to but thank you for explaining. I will add it as a feature request. I hope they are supportive of people wanting to use features differently than they were intended. After all, that is what innovation is. My email service provider allows unlimited, on the fly aliases which is heavenly and it made me use email in a different way than I used to. It's just tricky not to forget to input the correct from address every time. And I suppose I should give up hoping for the Android version of TB to ever work with aliases, which is too bad because now I cannot even reply (not found a workaround either) to an email I received to an aliased email address I sent from. Thanks again

Your webmail account allows you to do it because you are logged directly into the account.

Email clients need to communicate with server via pop, imap or smtp protocols in order to send what is allowed by server. Creating on the fly in Thunderbird would not be allowed by the server because it has to exist on server first. Servers are very particular about what they allow over those protocols. That means you have to use an 'alias' which has already been allowed by server otherwise it thinks you might be a hacker.

You may discover that whatever 'alias' you use in the 'From', the server still inserts your main email address somewhere in the headers as it goes from the main account as permitted sender. Check the header info in message 'Ctrl+U' or select email and use 'More > View Source' to see if anything is mentioned.

In Thunderbird it will download emails which you have allowed on server from various 'alias' addresses. It will then send using the default identity for the account using the smtp settings. It can send/reply using pre created 'alias' email address providing it has been instructed and server already knows about them and allows them from third party email clients.

re : I cannot even reply (not found a workaround either) to an email I received to an aliased email address I sent from.

You have not mentioned if you have added that 'alias' as an identity to the mail account or not.

I have a mail account with an additional identity, so I know it works. In 'Manage identities' for the mail account. I selected the additional non default identity/alias email address which I had created and click on 'Edit' On 'Settings' tab Private data: Select 'Reply from this identity when delivery headers match' In that area I typed the alias email address.

Have a look at this addon: I did find an addon which sounds like it can auto create the 'identities'. I cannot say whether this would work for you as I've never used it. Please note addons are not created by Thunderbird, they are the sole responsibility of the author. It's up to the author to make sure their addon works with the various versions of Thunderbird. So before you ever do any update, it might be worth checking to see if the addon has been updated accordingly.

Maybe you have a look at it as it might help with the auto creation if identities. https://services.addons.thunderbird.net/eN-US/thunderbird/addon/catchall-bird/

Thanks for the explanation, Toad-Hall.

I've been using identities without selecting 'Reply from this identity when delivery headers match'. The identities do what I want them to do: reply from the same identity to which a message was sent. What more does 'Reply from this identity when delivery headers match' do?

mailman-sup, you may be interested in this: https://github.com/thunderbird/thunderbird-android/issues/935

and this: https://support.mozilla.org/en-US/kb/using-identities

Thank you so much for your detailed and informative reply. First of all, my email provider allows any on the fly alias WITHOUT setting it up first (again, the no setup, on the fly feature is what revolutionises the way people use email) . This feature was the main reason why I subscribed to them. But I understand this is rare, so I should no expect TB to support it. I can tell you from personal experience that on the fly aliases is heavenly and I can never go back to "normal" email. Once more people see this, it may be more supported Of course you are wrong about TB not supporting it (that's exactly what "customize from addrress" is) and it is great when sending, just the replying is the problem

Secondly, I checked the headers carefully and they do NOT transmit my main email, only the aliased email. I even sent an email to a "regular" email service and checked there. I am so glad my privacy is not blown and I can use aliases just like a regular email address (minus the setup).

On the fly alias creation is the future of email, in my opinion. I am now using about 30 and adding more with any new email I am sending. When Im done with a person or subject I can block the alias on the server. As additional benefit is privacy. Makes harder for the spy agencies like Apple or Google to correlate and email to a date and another one to a doctor, for instance, if the email address is different (due to the aliasing) Thanks again. I will try the addon.

Toad-hall - thank you so much for your suggestion for the addon catchall-bird. It completely fixed it and TB is now replying with the from address that the email was sent to, as is should.