1. Load your Plesk Control Panel.
    This can normally be found at https://www.youdomain.com:8443 if you did not know already.

2. Login to the Plesk Control Panel with your username and password

3. Click the 'Mail' button once you have logged in.

4. You should now see this:

5. In the box next to 'Mail Name:' enter the name you wish to use. This will be the address before your domain, and also your username for picking up e-mail/logging into webmail.

So, as an example, if I entered 'joe', my e-mail address would be joe@yourdomain.com, and my webmail/POP3 username would be 'joe'.

6. Click the 'Add' button to the right of the box.

7. On the next page, tick the top 'Mailbox' tick, and fill in a password for your mailbox.

8. Scroll down to the bottom of the page, and click 'Update'

You should of now created your mailbox ready for collecting e-mail, picking it up via POP3 and your Webmail.