Click here to read a summary of Email Caching. This method will load into the cache all emails that it does not already have. Currently it will do a maximum of 100 emails. So, if there are more than 100 new emails (or first time on large accounts), it will have to be called multiple times  
  Account Numeric Mandatory
  Folder Numeric Optional. By default, emails are retrieved from your inbox. To see emails from another folder, pass the value as returned from MESSAGING_EMAIL_CACHE_FOLDER_SEARCH.
  FullRefresh Text Pass 1 to initiate a full refresh of the cache. This is required if emails have been deleted using other tools etc. It returns the most recent [MaximumDownload] emails.
  MaximumDownload Numeric Defaults to 100 for the Inbox folder, 30 for all other folders. Is only used if you are not passing StartIndex / StopIndex. Must be between 1 and 100
  StartIndex Numeric Use this in combination with StopIndex to obtain specific emails. As FullRefresh=1 only obtains the most recent 100 emails, you should use this parameter if you need to access older emails
  StopIndex Numeric  
  ExternalDelete Y/N. Indicates if emails have been deleted - usually to match if emails were deleted outside of MyDigitalSpace
  FullRefresh Y/N. Indicates whether a full refresh happened
  NewRows The number of new emails added to the cache. Use MESSAGING_EMAIL_CACHE_SEARCH to retrieve the emails
  Notes Used for passing back some information about exception conditions
  StartIndex Numeric. Only returned if newRows > 0. Indicates the first emailretrieved
  StopIndex Numeric. As per StartIndex, but indicates last email retrieved