I've got paypal, I don't get anything emails from paypal, though I've got my share of emails from scammers who want me to think they're paypal. Just to show that the scammers are doing shotgun and don't know, I also got the scammer emails for years before I actually signed up for paypal.
The way to find this out is to generate a new email address for each place you submit to, and use that address solely for submitting to that place. If any of those addresses gets spam, you can be pretty sure how it happened.
I've got a couple gmail accounts, it's easy enough to send yourself invites to make new addresses with. I'll send you a gmail 'invite' in exchange for a positive rep point.
Now that I think about it, it's been months since I've checked either one...