This is a expected behavior provided the users who have received the Request Access mail have share permissions on that file.
Whenever a user who requests for the permission on the file on which multiple users have Share Permission, The mail will be received by such random 10 users and the owner.
Kindly check the permissions on the file and remove the share permissions of the users, If you do not want the mail to go to other users.
In order to check the permissions follow the below steps:
1.Login as an OU Admin.
2.Go to Files Tab.
3.In the left pane filter out the file of whose permission needs to be checked.
4.Click on View Permission(Key Symbol) and check the permissions of the file. Also check if any policy have been applied to the same.
If the user does not have Share Permission and yet Request Access Mail is received then kindly write us back.