5310 MMS configuration issues

So, I bought a 5310 on ebay and it was unbranded, which kind of irritates me because unlike everybody else here lol I actually liked the t-mobile version that I used to have. Nothing I can do about that though coz the fw is at version 9.something. My problem is that I can't receive MMS from my friend's email. It's weird, it'll receive them from my email but not hers.. I dunno. But it won't let me send one to my email, it just says "Multimedia message settings not defined. Message not sent." But then I go to Message Settings > Multimedia messages > Configuration settings and it says "No settings found. Contact your service provider."

I googled it and found nothing that'd fix the problem. People with the same problem have contacted their service providers and they couldn't even do anything about it. Somebody please help, I got this phone partly because the one I had before was so good for emailing my friend (can't text because she's in a different country) and the rokr e8 that I have is not very good with emailing. And I really don't want to get a different one because I love the 5310 in general.