Microsoft Exchange couldn't find a certificate that contains the domain name
Event:
Microsoft Exchange couldn't find a certificate that contains the domain name mail.whchurch.org in the personal store on the local computer. Therefore, it is unable to support the STARTTLS SMTP verb for the connector Outbound with a FQDN parameter of mail.whchurch.org. If the connector's FQDN is not specified, the computer's FQDN is used. Verify the connector configuration and the installed certificates to make sure that there is a certificate with a domain name for that FQDN. If this certificate exists, run Enable-ExchangeCertificate -Services SMTP to make sure that the Microsoft Exchange Transport service has access to the certificate key.