Don't Mark Mail from Trusted Domains as Junk
If you have one or more domains you never want messages marked as junk from (such as a corporate intranet), you need to configure a hidden preference.
- Open Config Editor.
- Type "mail.trusteddomains" into the "Filter:" textbox.
- Double-click on that row.
- Enter a comma delimited list of trusted domains such as "postbox-inc.com,getpostbox.com").
- Restart Postbox.
Messages from senders in that domain will no longer be marked as junk.