ha_proxy_client - HAProxy protocol client module

• When configured for a binding or binding group Momentum will connect to the given ha_proxy_server and prefix the SMTP session with a PROXY protocol version 2 header.
• The dst_addr and dst_port will be filled in with the resolved MX, the src_addr will be filled in with the configured value of ha_proxy_src_addr if the destination family is IPV4, or ha_proxy_ipv6_src_addr if the destination family is IPV6. If you need to deliver to both IPV4 and IPV6 destinations then you must configure both options for the binding or binding_group.
• The ha_proxy_bypass option allows you to bypass the proxy and follow the normal delivery method on a domain by domain basis.
• It is the customers responsibility to configure a listener at ha_proxy_server that listens for PROXY protocol and forwards traffic based on dst_addr:dst_port.

A simple example configuration for HAProxy would be:

A simple example configuration to use that HAProxy in a binding would be:

The module supports a configurable health check.

• In order to flip the state of a server from plumbed to unplumbed, a certain number of consecutive failures or successes must be met. The configurations health_check_failure_threshold and health_check_success_threshold define the number of said failures or successes to be met.
• Health check will happen periodically, as defined by the health_check_interval configuration in seconds.
• All health checks will follow a specified health_check_timeout period defined in seconds. Health checks will be aborted once this timeout threshold is met.