Great advice from Seth:
If you sell something, set up an address like “email@example.com”. Put this on your home page, “contact us if you’re looking for more information or a price quote.” Sure, you’ll get a lot of spam, but deleting spam is a lot easier than finding customers. (Hint, ask your IT people to make it a mailto link, with a subject line built in. That way, you can use the subject line to find the good email).