Importing a list of the subscribers of a mailing list is not possible.It is possible to get a list of your subscribers' addresses. You can have the mailing list software send it to you in an email message. To do this, you need to do the following:

  1. Make sure that the options "Remote administration" and "Remote administrators can list subscribers" are checked on the Config page of the mailing list in question from the Mailing List section of the Control Panel.

  2. Add your email address as a moderator of the list.

  3. Send a message to mailinglistname-list@example.com, and the mailing list software will send you a message with the list of subscribers. You will need to substitute mailinglistname with the actual name of your mailing list and example.com with your domain name.