I subscribed to a mailing list under a forwarding e-mail address. But Thunderbird sends mails from my real address (a GMail account). I tried to send my first message to the list today, but it got rejected because "The email address used to send your message is not subscribed to this group." Is there a way I can put my forwarding e-mail address on my messages instead of my real one?
Tools > Account Settings
Then select the account. Doesn't matter if you have multiple accounts, it'll still work the same
Click Manage Identities
- The dialog window "Identities for [account name]" will appear
- The dialog window "Identity Settings" will appear
Fill in the details using the forwarding email in the "Email Address" and "Reply-to Address" fields
Click OK on the "Identity Settings" dialog
Click OK on the "Identities for [account name]" dialog
Click OK on the Account Settings dialog
Now when you want to write an email, select the email address/identity you want as the outgoing from the "From:" field.
Try the Virtual Identity extension. This will allow you type into the From field. However, be sure you SMTP provider will allow you to send from a false (for them) email address.
To install download the file provided on the website, then in Thunderbird 'Menu: Tools > Add-ons > Gear Icon (Tools for all Add-ons) > Install Add-on from File...', and restart your Thunderbird.
Usage is straightforward, click on greenish area to edit, click on white background area to choose any stored identities.
I appear to be able to edit my from address in Thunderbird (v52.2.1 for Linux), simply by clicking the "From" address in the compose window, and selecting "Customize From Address..." in the drop down menu.
This works for me because I have a lot of disposable email addresses, and sometimes need to reply from one of them. If you have a regular address you want to use a lot, adding a new identity as described in the other answer seems appropriate.
The TB feature "Customize From Address..." (see wu-lee's answer) is currently broken, see per message From-Header not used for SMTP MAIL FROM - the edited "From Address" is only used for the "From:" header line whereas the address stated in the TB Account Identity is used as Envelope Sender when TB submits the message to the MTA (Mail Transport Agent). This is totally unexpected and undocumented TB behaviour, and will likely cause issues like the one described in this Super User Question.
There is another, very lightweight addon called EDITSENDER. It allows you to edit
From:-details on the fly for each message you write (As long as your mail-server accepts this).
Edited to add (2016-03-15): It has to be noted that the add-on is not part of the official mozilla ecosystem. There is no external verification-process for this add-on, and it might do nasty things to/with your data at any time.
Add your forwarding address as a POP3/SMTP account in thunderbird. Then, make sure you uncheck the POP3 account settings options "check for new messages" and "automatically download new messages" so you don't actually download the messages from your forwarding account
For Thunderbird 3, the steps may be a little different.
Then, when you go to send a message, just select the account you wish to send from.