You can't actually email Lisa Simpson, but in the episode 'The President Wore Pearls (EABF20)' she tells her email address. The address is on the link below.
She's a cartoon and even if she was real does Answers.com not give out peoples private information like email, phone numbers, home addresses etc.
Chat with our AI personalities
Homer's email is chunkylover53@aol.com, he says it in a episode.
Be aware that someone is using an IM account with that name to scam people though, so please do not fall for it.
I'm not sure but I think it's thecodyrsimpson@hotmail.com
Bart, Lisa and Maggie
Last Exit to Springfield
Lisa pretends to be a boy in the episode "Girls Just Want to Have Sums."
Allison Taylor, Ralph Wiggum