Pissed at my MIL 😡

So I was checking my husbands yahoo mail to see if any jobs had emailed him back and I come across numerous emails from multiple magazines such as Fingerhut,Montgomery ward and even emails from Khols about charges that are in my husbands name. The reason that I'm mad is because these are the exact stores/magazines his mom shops from meaning she got cards and stuff in his name. This isn't the first time she's done something like this. She got 2 loans in his name somehow last year and never paid them on time so now he has the worst credit and I wouldnt be so mad if I knew she would pay the bills on time but she never does. I'll be having my first child in July and was hoping my husband would have good enough credit to get us our own place but guess that'll never. 
Do I have a right to be mad? Â