You have several email addresses, but it does not sound like you have separate mail accounts for each of those email addresses.

The 'From' email address will be whatever mail account you are viewing at the time. So if you had a mail account for each email address, then emails would be received into their own mail account, so when you click on 'Reply' it auto uses that mail account email address in From.

So if the email sent using another identity eg: 'B' email address was replied back to you and was received/downloaded into the 'A' email address mail account, then when you click on 'Reply' it will auto use the 'A' account email address.

Are you using one mail account for the main default email address, but added 'identities' - other email addresses to that account ? You would need to select the required email address if it was a different identity from the default. As per info at link: https://support.mozilla.org/en-US/kb/using-identities

Hi Toad-Hall,

Thank you for your reply to my query. I wasn't aware of identities but now I understand. However in my case I have set each email address up as a separate account (I have 10 accounts) and the identity for each account refers to the email address used by that account. The only thing I have noticed is that I hadn't completed the 'reply to address'. When I receive a reply it does come back to the email address that I sent the original email from. It's just that if I were to reply to their reply then it sends the reply from my default account. I hope that's clear. Basically, if my default email address is 'A', and I send an email from email address 'B'. The reply comes back to email address 'B', but my reply back is sent from email address 'A'.

Thanks, Donald

Please check this:

• Menu app icon > Options > General
• scroll to the bottom and click on 'Config Editor' button
• In search type: self
• look for this line : mailnews.reply_to_self_check_all_ident
• If this is set to 'False', double click on that line to toggle the setting to 'True'
• Close 'about:config' window
• Restart Thunderbird.

Hi Toad-Hall,

Unfortunately the value was already set to 'true'. It's not as if this problem prevents me from using Thunderbird but the way it's working isn't logical to me and it does mean that I have to be diligent in checking the email address that I'm sending from.