If you whitelist a sender in Spam Blocker, their emails will never be regarded as spam but arrive in your Inbox unhampered. I have whitelisted the whole "about.com" domain, for example, to make sure my About newsletters are never filtered away.
Whitelist a Sender or Domain in Spam Blocker
To whitelist a sender or domain in CoffeCup Spam Blocker:
- Select Setup.
- Click Add under Friendly Emails or Subjects.
- Type the email address or domain (preceded by '@') you want to whitelist.
- To whitelist all About newsletters, for example, type "@about.com".
- Hit Return.

