As part of an ongoing attempt to assure the public after Snowden revelations prompted concerns that the company cooperated with the government, Apple has begun encrypting email correspondences between its iCloud service and other third-party providers.
The company has always encrypted emails between iCloud users, but now will be using Transport Layer Security (TLS) to encrypt email chains between any provider and its iCloud users, according to AppleInsider. Although this security will protect most in-transit emails, those sent to providers who haven't implemented TLS will still be vulnerable to interception.
Other providers, including Microsoft, have also begun using TLS in its email services. Microsoft began using TLS for both outbound and inbound email on its Outlook service earlier this month.