Colleagues were incorrectly set up as external organisations on Deliverables Management and documents were issued using to/from these external accounts. We have rectified the issue and they are now internal participants, if we are to delete the External organisations would we lose the files and audit trail of files sent whilst they were External Organisations?
You can delete the External Organizations without losing the data, it will be available in the outgoing transmittals. The participants will show a warning (red warning sign be shown beside the email ID). I hope this helps!