Runbox

On protecting stored content Runbox comes last here. It encrypts the disks but not the mail itself, which leaves your stored mail readable to the server. There is no native PGP either. Where it pulls ahead is policy and jurisdiction. It is based in Norway, requires a Norwegian court order before it will disclose data, sits outside the US CLOUD Act, strips IP addresses from outgoing mail, and is employee-owned with no data mining. If your worry is legal compulsion and data minimization, Runbox can rank above Mailfence. If your worry is the provider reading stored mail, Mailfence’s at-rest encryption has the edge. Either one can be compelled to hand over plaintext in practice.