In the mail route configuration shown, how does the Protection Server attempt delivery to example.com?

When a mail route in the Proofpoint Protection Server is configured with multiple destination hosts, the system processes them in a sequential, top-down order. The first host listed is treated as the primary mail transfer agent (MTA). If the Protection Server fails to connect to this primary host, it will then attempt to deliver the message to the second host in the list. This process continues down the list until a successful delivery is made or all listed hosts have been attempted. This configuration provides a deterministic primary and failover delivery path for email.

A. The system uses a sequential top-down order for predictable failover, not randomization for load balancing.

B. Delivery attempts proceed from the top of the list to the bottom, not from the lowest entry upward.

D. A manually configured route is specifically designed to override the public MX record lookup for the specified domain.

1. Proofpoint Protection Server 8.18 Administrator's Guide

Chapter 8: Administration

Section: "System > Routes"

Subsection: "Configuring Routes > Delivery Tab"

Page 218. The guide states: "If you enter more than one host

the Protection Server will attempt to connect to them in the order they are listed." This confirms the top-down sequential attempt.

2. Proofpoint Email Protection Deployment Guide (On-Premises)

Section: "Configure Inbound and Outbound Mail Flow"

Subsection: "Configure Static Routes". The documentation explains that static routes are used to forward messages to a specific mail host

bypassing DNS MX record lookups. When multiple hosts are specified

they are tried in order

providing a failover mechanism.