Is there a way to send sell/send you these cards without mobile autheticator activated? I have 8 of these cards ATM.
Sorry, there isn't. By the time the trade had confirmed and gone though (15 days), the cards would have expired and become useless.
Anyway, apparently Steam is having some problems with traffic:
Sorry
The Steam Community is currently unavailable. Please try again later.
Error 503 Service Unavailable
XID: 3711530700
Steam has a lot of intermittent problems, especially considering the Summer Sale. It is no problem.