You can configure Thunderbird to automatically save sent, draft, and other special kinds of email in the folders you designate by taking these steps:
- Open Thunderbird.
- Access the "Account Settings" (It might be under Edit -> Account Settings, or the menu with three horizontal lines -> Account Settings or under Preferences -> Account Settings)
- Find your account, and choose "Copies & Folders"
- Select the folders you would like for each special type of email