I moved everything to Fastmail too, a couple of years ago, but I didn’t actually delete my gmail or Mac mail. I just have everything, including some other domains, forwarded to fastmail. But I’ve never thought about unifying contacts between Mac and Fastmail. Is there a way to have a single canonical contacts list that will sync to all devices?
I don't know much about Macs, Jeremy, but do know that Apple supports the CardDav protocol, so it should be possible?
Rob Fairhead, Nov 22 2017 on raretrack.uk