Your email address would be stored on one of Pokemaster's databases, as it is needed for the software to complete your sign-up, and for various other functions. However, nobody else has the ability to see emails.
The way we track connected accounts, and how I was able to deal with ShinyKabutops, is by tracking their IP address. These are unique numbers that are assigned to the network you use to connect to the internet, and are sent to virtually every website or service you visit. (Try typing 'IP' into Google -- it'll spit yours right back at you.)
We can see the IP you last used to login, as well as which you used for your 'last write action' as the software puts it (though it tracks more than just submitted posts). So if you have multiple accounts and you use them on the same network, we can find out very quickly. Fooling us with VPNs or dynamic addresses is difficult since you have to be aware of what IP was used for logins and interactions on both accounts -- and obviously we're a step ahead knowing what those are.