From OpenKM Documentation
Import users mails from some user mail account by IMAP.
Importation is made automatically by OpenKM each 60 minutes, depending network bandwidth configuration, and other parameters, refreshing time could be greater that this.
Attached documents are indexed too.
Importing mechanism creates a folder structure based on year, month and day to organize automatically imported mails.
Copy attached document
Using contextual menu on document and selecting the “Copy” option will appear a menu to select destination folder to copy attached document.
Download attached document
Using contextual menu on document and selecting the “Download” option will downloading the attached document.