How does Apple protect user data in iMessage?

Apple protects user data in iMessage primarily through end-to-end encryption. This means that messages sent via iMessage are encrypted on the sender's device and only decrypted on the recipient's device. As a result, no one in between, not even Apple, can access the content of the messages. This level of security ensures that user data remains private and secure from eavesdropping.

The other measures mentioned, while important in the overall ecosystem, do not specifically address the direct protection of message content like end-to-end encryption does. For instance, two-factor authentication enhances the security of Apple IDs and accounts by requiring an additional verification step when signing in, but it does not encrypt the messages themselves. Built-in spam filters help to reduce unwanted messages but do not provide content privacy. Limiting message storage on servers can help in managing data retention but doesn’t directly encrypt the messages. Thus, end-to-end encryption stands out as the core feature that actively protects the user's message content in iMessage.