Attachments (file not link) via trigger for automated transfer

We would like to run triggers for automated transfer of documents to a 3rd party (Order Entry). Our interest is to send a file (.pdf, .doc,.xls etc.), so that the file can be used for order booking and the agents order is also stored in zendesk support. 

Unfortunately a trigger can only provide a link for the attachment received and no file itself can be forwarded. For sure we can solve the problem externally, but for us the feature would be very useful (especially in B2B businesses).

Do you see further possibilities to settle things?