can use the Mass Subscribe function to upload a current subscriber list or paste in a lot of email addresses to subscribe to a mailing list.
- From your cPanel interface, go to Mail -> Mailing Lists.
- Find the list you want, click Modify, and log into the mailing list administration interface.
- Go to Membership Management -> Mass Subscription.
Here you can paste a list of email addresses (one per line) or upload a file containing the email addresses (one per line).