In order to bypass emails or domains that are blocked due to Grid IP reputation, Denial of Service (DoS) attack protection, Quality of Service, Bounce Address Tag Validation (BATV), Greylisting, and Disable strict MAIL FROM checking you can add these IPs to allowed list in Connection Management.
Allowed IP Addresses Use this page to manage the list of addresses you want to exempt from Connection Management restrictions. If connections are not rejected until after all recipients are known, sender domains and email addresses may be entered as well.
When the SMTP server receives a connection from an IP address on this list, it always accepts the TCP/IP connection. Connections from that IP address will not be throttled, deferred, or blocked, regardless of the settings on the Connection Management page. Email from that IP address will still be filtered for spam and other email threats.
Navigate to System Setup | Security Services | Connection Management.
Click the Edit Allowed list button. ( This is at the bottom of the page)
In the text box, type the IP address you want to add. If you want to add multiple IP addresses, you need to add them separately or enter an appropriate CIDR range (e.g. 188.8.131.52/24)
Click Add New Address. The IP addresses appear on the Allowed addresses list.
When Email Security is not a first-touch server and receives email from an upstream server that uses a public IP addresses, GRID Network effectiveness can degrade. To avoid this degradation, users can put public IP addresses on a server list to make the address look like it's part of the trusted network.
To add IP addresses to a Trusted Network:
Navigate to System Setup | Network, click Trusted Networks.
Click the Add Server button.
In the text box, type the IP address you want to add. If you want to add multiple IP addresses, put each address on a separate line followed by a carriage return.
Click Save. The IP addresses appear on the Server List.