Blocked somebody after sweep of their emails using the mail app for windows 8, and now i want to unblock their emails, but they aren't in my blocked senders list?!? Any help??

I blocked my girlfriend after a sweep of her emails using the mail app for windows 8, and now i want to unblock her so her emails come through, but they aren't in my blocked senders list and she's pissed off ha!! aaa!! Any help??