我收到了一个录取邮件，求问一个关于能否反悔的问题

我昨天收到了一个学校的邮件说可以录取我。是申请的ms，也没有提到funding和占位费之类的，但是让我2月21号之前就回复。这样的可以先表示接受再反悔么？因为现在还有很多学校没来消息。把信件内容附在下面，这是不是属于AD，而不是offer。希望各位大侠能帮忙解答，感激不尽！

Congratulations! The Department has completed its review of your application to the Master’s Program in Chemistry and has recommended you for admission for the term that begins in the Fall, 2013. Under separate cover, you will receive official notification from the Graduate School Dean.
Please let us know by February 21, 2013 of your intention to accept this offer.
Again, congratulations on your acceptance to the Master’s program. Sincerely


谢谢各位~~~

先con一个！！帮顶，希望我也能有个消息来