What condition must be met to enable Strict Encryption mode in Mimecast?

To enable Strict Encryption mode in Mimecast, a certificate that has a complete trust chain must be in place. This condition ensures that the encryption used is secure and that all parties involved in the communication can verify the authenticity of the certificate being used. A complete trust chain is crucial because it links the server’s SSL certificate back to a trusted root certificate authority, thus establishing a secure communication channel.

Without a complete trust chain, Mimecast would not be able to validate the identity of the sender effectively, potentially exposing data to unauthorized access or interception. Ensuring that the certificate is properly validated and trusted is fundamental for maintaining the integrity and confidentiality of the communications being transmitted under Strict Encryption mode.