List administrators can export their list's subscribers in 2 ways. In both cases the first step is to set the member addresses to 'No'.
Go to: Admin > Privacy options. Scroll to the bottom of the page to:
Show member addresses so they're not directly recognizable as email addresses? NO
1. Roster
Login to your list's administration page and in the browser address bar, replace 'admin' with 'roster'. For example:
https://lists.mydomain.com/mailman/admin/mylist
=>https://lists.mydomain.com/mailman/roster/mylist
This will display your subscribers addresses for regular and digest delivery.
2. Email
Send an empty email to your list's request service. For example:
To: mylist-request@lists.mydomain.com
Subject: who ADMINPASSWORD
Replace 'ADMINPASSWORD' with your actual administrator password.