Messages will deliver: You will begin receiving SMS and MMS messages from them again. Note: You will not receive any messages that were sent while the person was blocked; those are lost forever.
Will the person know I unblocked them?Not directly. There is no notification sent to the other person stating they have been unblocked. However, if they have been trying to call or text you unsuccessfully, they will notice their communications are suddenly going through. how to unblock number from phone