When someone sends to a mailing list of over 20 people (I pulled that number out of the air, but it looks close) it will see them as spam. But there is a setting to accept all mail from this person, so that one mailing list from BMW club, was fixed.

Just repeating that some people have Web Based Mail which usually includes filters, so there's another option.

Eudora also has some features which are common to Netscape, such as not having swiss cheese security like Internet Explorer.