Even the entire EU is in the process of negotiating the same agreement.
https://www.justice.gov/archives/opa/pr/united-states-and-ca...
https://www.justice.gov/archives/opa/pr/justice-department-a...
You can read the text right here:
https://www.justice.gov/criminal/criminal-oia/cloud-act-agre...
The same agreement is in place with the UK. Canada and EU are currently in the process of negotiating it.
Things have changed. With Chinese law in regards to data within Chinese jurisdiction a long-standing thing and an unfriendly American government potentially in power for an extended period, other countries are realizing the importance of data sovereignty.
> The latter states that negotiation with the EU on this topic was suspended in 2019.
Dated 2023:
> Justice Department and European Commission Announces Resumption of U.S. and EU Negotiations on Electronic Evidence in Criminal Investigations
The negotiations are still ongoing. Canada is further along than the EU.
The Five Eyes is an Anglosphere intelligence alliance comprising Australia, Canada, New Zealand, the United Kingdom, and the United States. These countries are party to the multilateral UKUSA Agreement, a treaty for joint cooperation in signals intelligence.
Does fastmail have a US presence? If no - then they're not bound at all by US jurisdiction.
See: https://roncobb.net/img/cartoons/aus/k5092-on-Tucker_Box-cuu...
The question is: do they office services to residents of said country / state.
If so they may well be subject to certain laws that, if broken, could result in penalties up to an including extradition of the responsible officers.