I'm trying to setup Zoho's Outgoing Gateway to relay all my outgoing emails to " relay.hes.trendmicro.com"  but I'm getting error when saving the configuration.

Verification Email Failure. The destination host you provided is not accepting messages sent to the email address provided. Please check with the email administrator. 

I already added the following Zoho IP addresses to the server 72.5.230.70 and 72.5.230.100 so zoho can relay the email.

Please help me with this.

Thank you in advance.

Regards,

Renan