Thunderbird doesn't have a traditional email whitelist. Instead, Thunderbird considers the contact list in Thunderbird as trustworthy so this serves the same purpose as a Gmail whitelist or Outlook whitelist.
To create an auto whitelist so that email addresses do not go to Junk:
- First, enter the contact you wish to whitelist in your Thunderbird address book.
- From the main menu go to Tools > Account Settings > Junk Settings for each email account you wish to configure.
- Check the box labeled "Enable adaptive junk mail controls for this account."
- Under "Do not automatically mark mail as junk if the sender is in", select the mail box(s) you wish to include to be whitelisted.
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- Additional but optional settings are below this to handle genuine spam messages.