The original message was received at Sat, 29 Oct 2016 18:41:58 -0700  from sales@domain.com.au [sales@domain.com.au]

    ----- The following addresses had fatal errors -----   

   [Status: Error, Address: <customerservice@domain.com.au>, ResponseCode 421, Host not reachable.]

Message will be retried for 4 more day(s)