On Mon, Dec 30, 2019 at 10:28:03AM +0800, Eliza Chan wrote: > Does it mean messages get encrypted in transfer process and message storage is > encrypted in rest?
That's a plausible definition, but transfer may not always be encrypted, since the provided typically would not refuse inbound mail that did not use STARTTLS. The responsibility to use STARTTLS falls on the SMTP client. > Why so many encrypted mail providers like protonmail, tunanota say > they have privacy advantages than traditional mail providers (for > example, gmail)? If they also encrypt messages at rest, then it is harder for unauthorised parties to access message plaintext. But you can read their documentation for any details that substantiate the marketing blurbs. -- Viktor.