Thunderbird is very nice and lightweight compared with outlook. Picks up email settings more quicker and is much simpler to use than outlook. Recommended to all my clients.

Especially 3D objects

I did a look into this. softmaker is best when it comes to compatibility of displaying files. Wps office is ok, but some text would be on top of others. I did find that there is a free version of softmaker, which should be ok.

I use lucky backup to mirror to external drive. And I also use Duplicacy to back up 2 other separate drives at the same time. Have a read on the data hoarder wiki on backups.