On the "Account" tab, fill in a name to identify it, your name (or whatever you want to show up in your email), your email address, organization, and a reply-to address (if different).
On the "Servers" tab, fill in the POP server that your domain host told you to use (Opera currently doesn't do IMAP). Your "Username" must include the "@mycrib.com" (substitue your own information, of course…). Put in your password if you want to. For the outgoing, use your ISP's SMTP server if you can; your mail will go out faster. Otherwise, use the server your domain host gave you.
The other tabs are personal preference selections.