Step 1: Log into your cPanel account.
Step 2: Open the Mailing Lists option from the cPanel menu.
Step 3: Set moderator password for the mailing list.
Step 4: Access the URL http://domainname/mailman/admindb/listname_domainname in the browser.
Step 5: Enter the moderator password and click on Let me in.
Step 6: Select Accept and then click on Submit all data.