Here is a way to know: Keep being in touch with them but don't send them any personal info about yourself (you should even use a fake name). Pretend to go with the process. And observe. Soon, they will ask you to send money to their lawyer in order to process your visa. DON'T send any money of course. If you were to send money (I repeat: Don't send any money, it's a scam), they would get back to you and ask money a second time for some type of deposit in your name in a bank account in the country where you will teach, as proof that you have enough resources to move to that country to work, or some other reason. And after they get the $, they would stop replying to your emails. If you proceed further with them, and you want to share the results on this board, that would help other potential victims.