I'm having this error when I send Zoho email to a university email. When I send the same message via other email accounts, I don't have this problem. 

ERROR_CODE :550, ERROR_CODE :5.7.1 74.201.84.163 explicitly prohibited from sending mail for this domainby sender's published policy 

I'm new to using Zoho Mail; does the highlighted portion mean that the school's email is denying specifically Zoho emails? 

Thanks!

-Lily