Office 365 received the message that you specified. Unfortunately, we haven't been able to deliver it to the recipient ({0}) ...

Office 365 received the message that you specified. Unfortunately, we haven't been able to deliver it to the recipient ({0}) yet. We can't deliver the message because we received an error when connecting to your organization's email server (on-premises server). Based on the error we received, it looks like your on-premises server isn't available to receive email.