Especially if you use Spam Sleuth with its — somewhat faulty — default settings and without its Bayesian filtering enabled exclusively, it's a good idea to add known senders (friends, newsletter publishers,...) to the Friends list to make sure they don't stand a chance of being filed as spam mistakenly by Spam Sleuth.
I have added the "about.com" domain to this lit, for example, to make sure all the About newsletters I have subscribed to get past Spam Sleuth unhampered — whatever their content may be.
Add an Email Address or Domain to Your Spam Sleuth Friends
To add an email address or domain to your Spam Sleuth Friends list:
- Select File | Configure... from the menu in Spam Sleuth.
- Go to the Friends category.
- Make sure Active is checked.
- Click in the entry field.
- Type the email addresses you want to whitelist.
- Put each address on its own line.
- To friends-list a whole domain, type the domain name preceded by "*@".
- To whitelist the "about.com" domain, for example, type "*@about.com".
- Click OK.

