Question

A financial services company must guarantee that all outbound email to a business partner domain (partner.example.com) is transmitted only over an encrypted channel. If encryption cannot be negotiated with the partner's mail server, the message must NOT be delivered in cleartext. Which configuration on the Cisco Secure Email Gateway meets this requirement?

Accepted Answer

Create a destination control entry for partner.example.com with TLS set to Required; if the TLS negotiation fails the connection is dropped and the message is not delivered in the clear

Answer

Create a destination control entry for partner.example.com with TLS set to Preferred so the gateway attempts TLS but falls back to plaintext delivery

Answer

Enable DKIM signing for the outbound mail flow policy to the partner domain

Answer

Add partner.example.com to an outbound content filter that applies the S/MIME encryption profile to every message