Sure, some of us used it to talk to him a long time ago. As far as anyone knows it hasn't sent any mail for years. GMX is a webmail provider by the way.
Before GMX Satoshi used a mail service specifically designed for anonymous usage, but he didn't want people to realise it was a pseudonym so he quickly switched to a more popular and generic host.
So what did you talk to God about? "Hey God, whassup? Love the whole Bitcoin thing but I have to tell you the pits in avocados are way too large dood." lol