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 Office 365 can't get the MX record information for the recipient domain. This usually happens when the domain's MX record isn't set up correctly at the domain's DNS host provider.