mail not work! Help plise

mail not work! Help plise

553 Relaying disallowed

Final-Recipient: rfc822;  office@nikamaritime.com
Action: failed
Status: 5.0.0
Remote-MTA: dns;  mx.zoho.eu . (31.186.226.32, the server for the domain  nikamaritime.com .)
Diagnostic-Code: smtp; 553 Relaying disallowed
Last-Attempt-Date: Wed, 21 Jun 2017 09:41:37 -0700 (PDT)

i'd dont now what to do with this