This HOWTO was inspired by a trouble ticket submitted from the guy who posted this question∞ in our ASO Forums.

This assumes that you have a domain example.com hosted at another hosting company, with a mailing list list@example.com that you want to host at ASO.

1. Rename your list to list@lists.example.com.
2. Edit your DNS records on your web/email host or submit a Support Ticket to your host to arrange the following:

lists.example.com IN NS ns1.asmallorange.com
lists.example.com IN NS ns2.asmallorange.com

This delegates the authoritative information for lists.example.com to ASO's nameservers so we can answer DNS queries and respond with the appropriate IP address.

3. Have your host export your mailing list membership information and configuration with the following commands (these options may or may not be available to you):

#mailman/bin/list_members -o members-info lists.example.com
#mailman/bin/config_list -o list-config-info lists.example.com

4. Set up your ASO account with the domain lists.example.com, rather than example.com (alternatively, you can add this as an Addon Domain under an existing account).
5. In Cpanel, click on Mail -> Mailing Lists -> Add Mailing List.
6. Upload the two files members-info and list-config-info to your home directory and send a support ticket∞ to have us import these files with the commands:

#mailman/bin/add_members -r members-info lists.example.com
#mailman/bin/config_list -i list-config-info lists.example.com

Voila! Your mailing list is now hosted on ASO!

If you want to continue using the email address list@example.com, you can add a forwarder or an alias at your other host to direct all email for list@example.com to list@lists.example.com.