Chat With Support and reference this article. 

Include the Campaign Name and Email Name and any copies of the original email. 

Also provide the header information for the original email which can be obtained through the following steps if you're using Outlook. Other versions of Outlook or different email providers may have different procedures. This needs to be obtained by the supporter the email was sent to directly:
  1. Double click on the email in outlook to open it in a new window
  2. Click the file tab in that window
  3. Click Info 
  4. Click properties
  5. Copy all the text in the Internet Headers box and paste that into an email or the case notes