Same email-different accounts

I am the admin of a new site and I need help please. I can't seem to figure out how to allow people to make multiple accounts with one email. Is this possible? If so, how do I make that happen?
Thanks a bunch(:

It is not possible.

Hello,

As SLGray stated above, it is not possible to allow someone to sign up for multiple accounts with the same email, however, if someone wants multiple accounts and does not want to create a new email account for each one, that person could just create the account with a fake email address and an admin could just activate each account manually for them .

-Brandon