How do I get my old emails from Comcast into Outlook?

I have figured out how to forward new emails from Comcast to Outlook. But cannot figure out how to import / transfer / migrate / move / whatever PREVIOUS emails already in the Comcast account over to Outlook. Search results all say to use TrueSwitch, but it's no longer operational. Only method seems to be to forward each one. No good. I can forward a bunch at a time as attachments, but then they don't "un-bundle" on the Outlook end. No good either. Only a week until the Comcast account expires. Can someone help? Not terribly techy, but understand the basics, and I see that clear instructions are often given. Thanks.