I have no personal experience with mmyy.com....and I checked in Google ,with their official website,I found that there were many complaints against them....I just did a whois search using WhoisXY.com and they have hid their information using private registration.So, even if you need to contact the admin regarding any information you would need the permission from the third party to contact the owner.This would make the whole process difficult.When I ran a scam alert scan using Webutation.net I found that they have low web of trust rating.
Hence my advice is you better heed to any personal experience from a well known member and act accordingly.