The internal transport certificate that is used for SMTP authentication by Microsoft Exchange could not be read from Active ...

The internal transport certificate that is used for SMTP authentication by Microsoft Exchange could not be read from Active Directory. The certificate may be corrupted. If an existing certificate that matches the fully qualified domain name (FQDN) of the server is already installed, run the Enable-ExchangeCertificate cmdlet to publish this certificate to Active Directory. If a certificate for the FQDN of the server is not installed, create an internal transport certificate by running the New-ExchangeCertificate cmdlet for the FQDN of the server.