You can edit security settings for files shared anytime after sending.
When you edit security settings of a file, changes are applied in real time. To change settings,
Go to Sent.
Select a file you want to edit.
3. Find the options row on top of the page and click Settings.
4. Edit the security settings for the file, including
5. When you're done editing, click Save Changes.
Note that as each file has different security settings, you can edit settings one file at a time.