Since there is no calendar in Thunderbird that area is toasted. Contacts and emails should be transferable.

--> BEWARE THE SPAMMERS about OLM decoders and such. Just ignore them. finds the prior discussions so I can see why you had Tbird troubles.

PS. Yes, I know about but I will not offer those since I've heard from folk that locked up or lost calendar information with those. My nod would be to try the Apple Mail and Calendar apps.