If the header and footer isn't present in the email message body, then it is most likely contained in the email Stationery. First edit your email message and find out which Stationery it's using.
  1. Email > Email Campaigns
  2. Select the Campaigns tab
  3. Find the Campaign that your message is in and click Manage
  4. Select the Messages tab
  5. Find your email message and click Edit
  6. Go to step 3. Stationery
  7. Find the Stationery that has the radio checkbox selected and notate the name
  8. Select Email > Stationery
  9. Search for the name of the Stationery notated in step 7
  10. Click Edit
  11. Go to step 3. HTML to edit the code
  12. Click Save when finished