MESSAGING_EMAIL_CACHE_ATTACHMENT_DOWNLOAD Messaging Endpoint
  /rpc/messaging/?method=MESSAGING_EMAIL_CACHE_ATTACHMENT_DOWNLOAD  
  Click here to read a summary of Email Caching. Use this to download an attachment. The details of the email needs to be cached. Pass the id of the attachment, as returned by MESSAGING_EMAIL_CACHE_ATTACHMENT_SEARCH  
  PARAMETERS TYPE NOTES
  Id Numeric  
  RETURN