Central email gateway zimbra Inbound Problem

Hi, everybody

I've made all the settings, but I can't get mail. MX setting domain verification, etc. 

I use a Zimbra mail server. 

Central email settings display 2 IP address, called Sophos Delivery IPs (18.220.12.142, 18.216.7.10). what do I need to do on the Zimbra server to these addresses.

I want to use central email gateway only inbound mailing.

By the way, the following error message is displayed:

Your message wasn't delivered because the destination email system rejected your message for security or policy reasons. For example, the email address might only accept messages from certain senders, or it might not accept certain types of messages, like those larger than a specific size.

Contact the recipient (by phone, for example) and work with them and their email admin to determine what policy or setting blocked your message and what you should do to make sure that future messages from you won't be rejected.

For more information, see Status code 5.7.1.