This situation sort-of landed in my lap. My older brother set up custom domain email with the family surname for himself, parents, and another sibling many year

This situation sort-of landed in my lap. My older brother set up custom domain email with the family surname for himself, parents, and another sibling many years ago, but he died a couple of years ago, and as the only other techy person in the family, I've kind of taken on responsibility for these things, even though I don't use it myself. I was putting off migrating to another service, so I'm glad I don't have to worry about it anymore. (I was going to go with Apple iCloud+ because they're all pretty invested in Apple stuff anyway, but the process of manually transfering each person's email archive with Google Takeout was a bit of an unknown for me.)