Everyone participating in NaNoWriMo gets to send messages to each other using NaNoMail. It is just like email. It allows you to send mail to other participants without having to know their actual email address.
You can NaNoMail someone by clicking on the "NaNoMail Me" link in their profile.
If you do not want other users to contact you via NaNoMail, un-check the box under "Edit User Settings" that says "Allow private messages."
