I fear you'll have to try that.

Since you are on a new PC why not change to Thunderbird if you need a mail app? With it being on Apple, Linux and Windows it makes moving the mail storage around a lot easier.

Labels? I don't use them and https://www.macworld.com/article/2033842/make-mail-and-gmail-play-nice.html while dated does note which labels don't work. So I'm going with labels and Mac Mail are not compatible.