It’s not. I have no affiliation with mailbox.org. I’m simply a customer, same as I’m a Fly.io customer.
Why do you think this is off-topic? Fly.io is a US company, so it’s totally on the topic. CLOUD Act has been discussed before, BTW. But that was when you had a president that didn’t have a crazy billionaire sugar daddy.
Please read the linked blog post, it’s substantiated. If you wonder whether you should take the caution in the article seriously where it says
Data protection activists like Max Schrems are already warning that US cloud services could soon be considered illegal in the EU – similar to the predecessor agreements Safe Harbor (2015) and Privacy Shield (2020) that were overturned by the European Court of Justice.
It refers to this Max Schrems, so I’d rather listen. His NPO NOYB wrote about it before:
US Cloud soon illegal? Trump punches first hole in EU-US Data Deal