Here are a few tips for setting up filters:

• If you want to sort mail according to who sent it to you, enter the sender's email address in the "To/Cc header:" field. This is the best way to set up this kind of filter. Entering words the sender sometimes writes in their emails in the "Body:" field won't work as well, because other people might use these words, too.
• If you want to sort mail according to what is inside the message (all messages having to do with tires, for instance, going into a special "Cars" folder), then enter the words that interest you ("tires," for example) in the "Body: contains" field.
• For best results, put your "narrowest" filters at the top and your "broadest" filters at the bottom. "Narrowest" means your most selective filter; "broadest" means the filter that could apply to the most messages. When a message matches a filter, it goes where that filter tells it to go. None of the lower filters will apply to it.
• Entering the same word in all four fields (Tugboat Tugboat Tugboat Tugboat) requires the word to appear in all four fields (From: Tugboat, To/Cc: Tugboat, Subject: Tugboat, Body: Tugboat) for the filter to work. That probably will not happen very often, so this would not be a good choice for a filter.