Technically it didn't fail, it's been delayed.Look at the header info on the rejection the email. It should provide a reason as to why it wasn't delivered.
Delivery to the following recipient has been delayed:
jonpaulmorrow@evca.emailnb.com
Message will be retried for 1 more day(s)
Technical details of temporary failure:
Google tried to deliver your message, but it was rejected by the server for the recipient domain evca.emailnb.com by mx.emailnb.com. [167.89.125.4].
The error that the other server returned was:
454 4.7.1 <jonpaulmorrow@evca.emailnb.com>: Relay access denied