[Unit]
Description=Ensure Performance West mail sending IPs are bound to ens18
After=network-online.target networking.service
Wants=network-online.target

[Service]
Type=oneshot
RemainAfterExit=yes
ExecStart=/bin/sh -c "for ip in 207.174.124.72 207.174.124.94 207.174.124.107; do ip addr show ens18 | grep -q \"$ip/\" || ip addr add $ip/23 dev ens18; done"
ExecStart=/usr/sbin/postqueue -f

[Install]
WantedBy=multi-user.target