Which feature in Exchange is specifically used for ensuring safe email transmission?

Transport Layer Security (TLS) is the correct answer because it is a cryptographic protocol specifically designed to provide secure communication over a computer network. In the context of Microsoft Exchange, TLS encrypts the transmission of emails between mail servers and clients, ensuring that sensitive information is not intercepted during transit. This is particularly important for protecting confidential or proprietary information exchanged via email, which is a common vector for data breaches.

While Active Directory integration is essential for user management and authentication within the Exchange environment, it does not directly contribute to the security of email transmission. Anti-spam filters help to protect inboxes from unwanted or malicious emails but do not focus on the encryption or secure transport of emails. Mailbox recovery features are crucial for data integrity and backup, but they pertain to recovering emails rather than securing their transmission. Thus, TLS plays a vital role in maintaining the confidentiality and integrity of emails sent and received through Exchange.