How to avoid spam? A solution is to only open emails from people that are on your contacts list. But then it will be impossible for people to contact you if they are not on the contact list.
To get on your contact list people have to register their email address at your homepage. To avoid spammers from registering, they also have to recognize a word displayed by a picture, and type it in. There are tools for generating such pictures automatically from a dictionary.
This is the only real solution I can think of. And it will not be difficult to write a CGI script in Python that can handle the registration. I wonder if it has been done already, do you know?
Hey, the word-in-a-picture recognizing thing is also a solution for "blogspam", or guestbook spam.