Shadow

Salt water.

I yoloed from a year old version up to the latest, it was fine.

Valid, but it’s run by a group in the UK that runs several of the popular ones. It’s prooooobably not going anywhere.

Sh for shell scripts.

This. Go pick up something like a used Lenovo Tiny. You’ll get way more power and flexibility

Imapsync works well, have uses it hundreds of times on massive accounts. Not with Gmail specifically though. I’d imagine you would lose labels.