For the purpose of examples, we will pretend that your domain name is "yourdomain.com". Naturally, you will replace any instance of "yourdomain.com" with your own domain name.
To access the administrative pages, use your browser to go here:
http://mail.yourdomain.com:8010/
Login as "postmaster", using the FTP password you were given for your account.
Once logged in, you will see a list of the mailboxes you currently have in your domain. Most hosting accounts include ten mail accounts, including the postmaster account. You can create any number of aliases, forwarders, and groups.
To create an account named "info@yourdomain.com", you would enter "info" in the box next to the "Create Account" button. Click "Create Account" and you will be taken to a detail page for the "info" account. You only need to adjust two things: the Real Name field should contain the name of the owner's account. The Password field should be set to whatever password you want to use for this account. Then hit "Update," and after the page refreshes, you can click on the "Accounts" link to return to the main page for your domain.
An alias is another name for an account. For instance, we can give the "info" account an alias named "sales," so that mail sent to either "info@yourdomain.com" or "sales@yourdomain.com" will land in the info account. To create an alias, click on the account name to go to the account detail page. Scroll to the bottom and enter the alias in a blank field in the "Aliases" section. Click the "Update" button and you're done.
A forwarder works similarly to an alias, but it can forward to any address, not just the mailboxes in your domain. For instance, you could create a forwarder named "webmaster" that sends mail to your private email address, "foo@bar.com". Simply click on the "Forwarders" link near the top of the page on the right side. You will see a list of forwarders; the left side is the address in your domain that receives the message, while the right side is the address to which the message should be forwarded. For this example, you would simply enter "webmaster" on the left and "foo@bar.com" on the right, and click "Update."
A group is like a forwarder that forwards to more than one address. For instance, you might create a group named "sales-team" that forwards to "foo@bar.com", "bar@foo.com", and "betty@boop.com". To create a group, simply enter the group name ("sales-team" for our example) next to the "Create Group" button, then click the button. This will take you to a page where you can enter the addresses of the group members, and set various options for how the group mail should be handled.
Please note that a group is not a full-fledged listserver, like Mailman or Majordomo. We do offer list services using Mailman; please contact your account representative for details.