I don't use Thunderbird any longer but if I remember right, can't you set one Thunderbird mail account as the default? You would that in your Thunderbird "Account Settings".

I'm using SeaMonkey Mail which is similar to Thunderbird, and it lets you go to the Mail Account Settings, select the account name, and click the "Set as Default" button. That way, that particular account is used for the email composition for mailto actions.

If you need help with setting a default mail account in Thunderbird, please ask a new Thunderbird question.

I have a similar problem. I have several email accounts in Thunderbird, a university account, and several personal.

In Thunderbird/account settings I have VERIZON as my default outgoing server. When I write, forward or reply to an email, TB uses my Verizon email address in the FROM field.

In Firefox/options/application/mailto: I have Thunderbird default as the value.

When I email a link from FF, it comes up in Thunderbird and displays my university email address in the FROM field. I want FF to send emails under my VERIZON address.

I believe, from what I have read in support, that I have the correct settings in both programs. Why is my university address appearing when I use mailto: in FF?

To ttarr, Thanks for posting that you also have a problem with Thunderbird not using your default account in the "From" address for Firefox mailto links. My default mail client is Windows Live Mail and Firefox correctly uses whichever account I set as the default in my Windows Live Mail settings. I just tested it, then I selected a different default account in Windows Live Mail, closed WLM and tested it again, and both times Firefox used my default account in the "From" address.

Maybe it would help if you changed your default account in Thunderbird to a different one, close and reopen Thunderbird and set it back to your preferred account? If it doesn't help then you should start your own support thread by using this ask a question link. (See Mozilla Support rules and guidelines: For support requests, do not re-use existing threads started by others, even if they are seemingly on the same subject.)

To cheryli1964, are you still in need of help?

I did a little digging online, and found a thread about rearranging the order of your email accounts in Thunderbird.

I went to config manager and rearranged the order of my accounts and moved VERIZON to the top spot. After reloading Thunderbird, Firefox now correctly shows VERIZON as the return address.

mail.accountmanager.accounts is the object to change.

The accounts are listed in a string. (account3,account7,account4,account5,account6,account2,account1)

Changing the numbers rearranges them on the tree view.

The account # identifies are listed a bit further down below mail.account.manager.

Thanks for your reply. Its good to know that others are willing to help.