Its spam.......they send this message that you have a card then make you log in to pick it up.....the catch is that you have to register to log in......thus getting spammed more!!
Thats how I know what they do........felt guilty cause I thought someone in my family sent me a card and signed up (sighs....feeling very stupid). Junk Mail folders are good things!!!!
I got one at my private "never before spammed" personal email address. Because it came to that address I opened it and I got spammed the first time 1 day later and now I get dozens.