Can wife open/take husband's mail

As I was restricted by the court, I cannot visit my apartment to get mails.

However, I just found that after my wife transferred all the money from our joint account, she's even open the mail that's writing to me and deposit the check into our joint account.

Is it even legal for her to do that?? How do I fight for my rights?

I double checked with the person who wrote me the check. Here's what she replied:

XXX,

I wrote all three checks out to XXX..

I addressed the envelope to XXX at your YYY NY address.