How do I sync Google Apps mail with Mail 5.3?

There's a post here about setting up Google Apps email through MS Exchange on Mail.app 5.2, but this doesn't work for me in 5.3.

The email I've been using for well over a decade is from a former dial-up ISP (Worldshare.net) and I am paying $10/year to keep the address. They've since moved mail to Google Apps.

I'm looking to close that account, but I'd like to save some of the messages, preferably in Mail.app format. I'm looking at no more than 200 messages and, if I could only get those into Mail.app, I can preserve them in a folder "On my Mac."

I opened a standard gmail account, hoping to Import these Google Apps messages, from which they could be accessed in Mail 5.3, but gmail won't accept the Worldshare IMAP credentials. I've enabled POP on both accounts, but still no luck.

Any thoughts on how I might get this done?

Thanks.

PS: I am also unable to set up this Worldshare Google Apps mail account on iOS6.