How can I tell if an email from a debt collector is a scam or legitimate?

Whenever a debt collector contacts you, the first thing you should do is send them a validation letter which asks them to validate the debt in question to be indeed your account. They will then need to respond with validation documentation so you can indeed verify that the debt they are trying to collect on is yours. If they cannot validate, they may be contacting you as a scam. In either case, never give out your banking information even as a postdated check to a debt collector to make sure your information is protected.