If you need to create your mailbox see the previous guide
1. To switch on anti-spam on your mailbox, first login to Cpanel, then go to Account Information > List Accounts, Click on the domains CP logo > then click on the Apache SpamAssassin button.
2. Click Enable Apache SpamAssassin. This enables the filter for all mailboxes. You can also change the spam sensitivity here as well.
3. (Optional) - Click on Configure Apache Spamassassin - here you can manage sensitivity options, along with White List and Black List options.
6. Click 'OK' to save and finish.
Note: Your server with Nimbus is capable of being used as a basic mail server, but the ongoing battle between spam management, hacking and blacklisting means that Office 365 and Google Apps are the go-to platforms if email is critical to your business/site. Read more here.