wix file share app grant folder permission to nickname not email

If two users have the same firstname in their email, how do we differentiate which siteMember folder permission should be granted to.

any pointers will be a big help…as we might be having 6K users onboarding and for each admin need to create a folder. If onboarding happens with same name like this info@xyz.com and info@abc.com
how will an Admin differentiate?