import java.util.Map;
import com.adeptia.indigo.event.EventUtils;
import com.adeptia.indigo.event.mailtrigger.MessageDigest;
import com.adeptia.indigo.system.Context;


Map eventMap = (Map) context.get(EventUtils.EVENTCONTEXTVAR);
if (eventMap != null) {
	MessageDigest msgDigest =  (MessageDigest)eventMap.get(EventUtils.MAILMESSAGE);
	if (msgDigest == null){
		throw new Exception("Process Flow is not triggered through Mail Event");
	}else{	
		String attachedFileName = msgDigest.getAttachment();
		context.put("attachedFileName", attachedFileName);
	}
}else{
	throw new Exception("Process Flow is not triggered through Event");
}