没有收到电话面试，本以为被默据了

之前看到地里好多人收到电面邮件，我就以为自己被默拒了，看来不是这样。
我成绩低的可以，也没有认证什么成绩，疙瘩网申时候填成绩的单子也是自己随便换算的。。。
不过有个问题，我什么都没答复呢，就收到另一封信：
Congratulations on your acceptance to the Master of Science program in Computer Science at Columbia University. My name is Remi Moss, and I am the Assistant Director of Academic Programs in the Computer Science Department. I wanted to send you an email to personally congratulate you on your accomplishment.
这是怎么回事。。。？？地里其他收到ad的同学是这样子么。。。？求解答
Bless all！