When you registered in pbemtracker you supplied your email address.
After D!CK and rd13 also register in pbemtracker, Michkov can then edit the game.
This puts everyone in correct play order, and enters their in-game name.
After you have played a turn, you simply login to pbemtracker site, and choose an 'upload fille' option, and your save will be uploaded, with the name checked against the names held in pbemtracker. pbemtracker automatically emails the save to the correct next person.
It also holds the file as an available download - so if the email got lost, the receiver can login to the site and download it again, without having to ping the sender and wait for a new save to be sent.
The site prominently displays who has the game at any one time, so when we get a holdup Michkov knows who to email to find out the delay. There is a 'view turns' history so we can see if everyone is playing at the average pace, or if one person is regularly holding it up.