You might want to edit the kB number out of your message, or it will be possible to rougly figure out which Crystal Web username corresponds to your forum account.
Well, first I calculated the size of the total leak. I did this by measuring my own username's placement in the previous two leaks to get an idea of how big the current leak is. When measuring the previous leaks, I came out with very close to the same fraction on both leaks. Dividing the amount of usernames received in today's email by this fraction gave me a good estimate of how many accounts were leaked today, and thus also how many emails were sent.
Each email contains information about the user in question, and all users before that user alphabetically. So the first email contains information for one user, the second email contains information for two users, and so forth, up to the number of accounts leaked today. thus 1+2+...+n, which is a total of 1730730. Then I took the size of the email I received, minus all headers, and divided it by the number of accounts contained in my email, which gives the average size of the information for a single account. This number was then multiplied by 1730730 for a total of 630MB.