I use Eudora also, and find it a good email program. I suggest the best approach to most spam is to delete it and forget about it. Eventually, for whatever reason, the person sending you the spam seems to forget about you and the spam stops. Don't send them any responses, or you move up to the A list which lasts a LOT longer.

The only exception is mail received from well-known companies that you have dealt with in the past (banks, credit card companies, retailers, etc.). If you get on their advertising list, there's usually a link in the mail that will allow you to opt out of their mail solicitations. They want you as a long term customer and really don't want to offend you with unwanted email.