Mojang (specifically, Tobias Mollstam of Mojang) broke part of the minecraft.net website that sends usernames to Classic servers, a few months ago. Instead of a username, it sends players' email addresses associated with the Mojang account. At first everyone thought it's a bug that'll be fixed, but looks like it will never be fixed at this point. So, fCraft adds a workaround.
Since there is no way to look up the actual username, server has to go by email. To avoid pasting players' full email addresses in chat (which is a privacy issue, and too long too), fCraft software cuts off the domain name. For example, [email protected] becomes [email protected]. The @-sign is part of the username -- names admin and [email protected] would refer to totally different players. If someone with same name but a different domain connects, they get a number. So if [email protected] after [email protected], they'll become [email protected].
Names of email players are verified, just like normal usernames, so there is no additional danger of impersonation.
- Only players with ViewEmails permission can view players' real emails in
/Info. By default, only the owner rank has this permission.
- Email players can be blocked from joining the server by unchecking "Allow email players / Mojang accounts" on the Security tab of ConfigGUI, or by setting AllowEmailPlayers key to
config.xml. It's not recommended, as there isn't any advantage to it.