You can export email addresses from mailman mailing list to txt file using the following command.

1. cd /usr/local/cpanel/3rdparty/mailman/bin/
2. ls to see the mailing list
3. /usr/local/cpanel/3rdparty/mailman/bin/list_members_domain.com > address.txt
4. Copy this address.txt file into public_html folder of user account.

If you require help, contact SupportPRO Server Admin