That data is stored on the database... I'm sure there's a user management related mod/plugin that let's you send an e-mail to all users (if that's what you want). If your talking about making your own mod, the just list the e-mails stored in the users table. If your looking for an easy way, search punres for a user management mod. I remeber hearing about 1 or 2 that let you send off e-mails to all registered users... forget what they were called though
PS: In a "vanilla" or original punbb install you have to click on each user in the user list, and then in thier profile you can see the info (if your an admin, I think if your a mod too?)
echo "deadram"; echo; fortune;