Dissect an email you have received. First, get the original, ASCII text of the email, including the headers, and the blank line separating the headers and the body of the email.
You can find an email that uses MIME; find an interesting email that perhaps also includes inline images.
Dissect that header to find the path of machines through whice this email hopped. Please try to find chains of at least 2 machines for full credits. Please try to find a header using SPF and show and justify the SPF rating, or with DKIM and explain.