I use Thunderbird to access several email accounts. When I open the address book and right click a name, and select "Write", the email form opens with my oldest email account in "From". The address book was started when that account was my only email account. However this is no longer my preferred email account. How do I change the "From" account that address book uses? I haven't found a setting for this.

I'm using Thunderbird 24.6 on Windows 7.