There are two types of email accounts: Users and Aliases. Both of these are explained in this topic.
Users - An email user account represents a person's actual mailbox. User accounts can receive email, send email, and log in to the web mail interface.
Aliases - A user alias represents a forward to an actual email account. The sole purpose of a user alias is to forward email to other accounts. Aliases may not send mail, and may not log into the web mail.
As a domain administrator, you can manage email accounts from the Email Accounts page in the Settings menu.
Add User - Clicking this button will let you add a new email user. More information about adding user accounts can be found in the topic Adding a User Account.
Add Alias - Similarly to adding a user, clicking this button will allow you to add a new user alias. More information about adding user accounts can be found in the topic Adding a User Alias.
Set Catch-All - A Catch-all is a special option set for a single alias. The alias assigned the catch-all will receive all email for a domain that is not targeted to an existing user or alias. Using a catch-all is usually not advised, as it gives spammers the idea that the email addresses are valid, and you may receive more spam as a result.
Edit an account - Edit an account by clicking on the username of the account in the table
Deleting an account - To delete an account, click on the delete link next to the account's name. Note: Deletions are permanent, and once an account is deleted, the mail cannot be retrieved from it.