In VPOP3 a List is a way of sending email to a group of email addresses. There are two types of List in VPOP3:
•Distribution Lists - simple way of distributing mail to a group of email addresses with no options.
•Mailing Lists - more flexible way of distributing mail to a group of email addresses with many options.
There are also Groups which are slightly different in that they can only contain local users and aren't as configurable.
Lists can contain local email addresses and remote email addresses. You can also include lists inside other lists, and they will be expanded as necessary.
To send messages to a List, you simply send a message to the <listname>@<local domain>, so if your domain is example.com and the list is called distributors, then to send a message to the list members you would send it to firstname.lastname@example.org.