Every time i tried send email from google to my zohomail, it bounced back with a message below.  but if i send email from hotmail, it goes through.  what to to to solve this problem? 

Technical details of permanent failure:
Google tried to deliver your message, but it was rejected by the server for the recipient domain  kapressconsultant.com  by kapressconsultant.com .  [66.96.147.103 ].

The error that the other server returned was:
550 bosauthsmtp16: Host  209.85.215.50 : No unauthenticated relaying permitted