Step 1: Click on 'Viewers' for the desired file.
Step 2: Click the three dot 'More' menu next to the desired viewer. From the dropdown, select 'Resend Email.'
Note: You can Adjust Security Permissions from this dropdown before you select 'Resend Email.'
Step 3: The 'Share' panel pops up with the recipient(s) name and previously selected Security Permissions already entered. Make adjustments, enter an email message if you choose, and press 'Send.'
Note: You can select multiple recipients in the Viewer List and resend email to all at once.