Duplicate Emails in List


So I have a test list and was able to add my email more than once. Why wouldnt the email field be unique? Why does it let you add an email more than once? Does this mean when I unsubscribe from that email there will still be another one left? Does it mean the subscriber will get emailed twice when I send to that list?
You shouldn't be able to add your email more than once in your list. if you were able to do so, it means there's an issue somewhere.
Can you PM me with access to your app where you added more than once same email?
Also FTP access would be awesome, to fix the issue, if any...