If I'm reading this correctly you've got it the wrong way around...
You have your email provided by Opera, which you pay Opera for... Is that statement correct? (If that is not correct then I don't think you can get your opera email via an email client... you have to read/write it via a web browser.)
You want to use Netscape communicator as the tool to read the email... Is that correct?
If the answer to both is correct, then, (and I'm not familiar with communicator so I'm guessing!), it will be something like "pop3 mail .opera.com" not, as you are suggesting "pop3 mail .aol.com"
I hope this makes sense, and is of some help! My apologies if it's just muddied things!