mail bounced back, owing to "email from dynamic IP"

mail bounced back, owing to "email from dynamic IP"

domain : 
ntlab.hk

this is the quote :

host  mx.zoho.com [165.254.167.50] said: 550 Mail rejected by  for policy reasons. We generally do not accept email from dynamic IP's as they are typically used to deliver unauthenticated SMTP e-mail to an Internet mail server. http://www.spamhau