PostPet is an e-mail software that uses a pet to send e-mails. If another user has the program, your pet can show up at their house to deliver the mail. You can also take care of the pet, feed it, wash it, etc. When it delivers mail to other people, it\'ll write a secret diary and possibly find treasure on its way home. You can also send normal mails with it but it\'s a really old program (windows 95/98) and only reads text e-mails.