Manually hiring a relief teacher would require you to make some calls, source some probable candidates and manually go through each of their credentials or resumes before you can even begin to short list. airTeacher is designed to relieve you off the long and tedious process of hiring a relief teacher for your school.
Never pay down a deposit in a bank account until you have met the seller, seen signed a purchase agreement. No serious private advertisers ask for a down payment before you meet. Receiving an email with an in-scanned ID does not mean that you have identified the sender. You do this on the spot, when you sign a purchase agreement.