From - Mon Jun 02 19:00:00 2008 Content-Type: multipart/mixed; boundary="bou" Message-Id: <123456@example.com> Part 1 --bou Content-Type: multipart/related; boundary="bound" Part 2 --bound Content-Type: multipart/digest; boundary="boundar" Part 3 --boundar Content-Type: multipart/alternative; boundary="boundary" Part 4 --boundary Content-Type: application/octet-stream Wow, what alternatives! We're trying to confuse the parser here. --bou --bound --boundar --boundary Content-Type: application/pdf A choice between a PDF and an octet stream! How marvellous! --boundary-- --boundar Content-Type: multipart/mixed; boundary="boundary123456" --boundary123456 Content-Type: text/plain This is the correct answer. --boundary123456-- --boundar-- --bound Content-Type: text/plain One last attempt at confusing the parser. --bound-- --bou Content-Type: text/html No harm in making another. --bou--