Consolidate the outbound mail footprint to match the SPF intent (already
trimmed to .94/.107 on 2026-06-19). A 20-IP sending footprint reads as
snowshoe spam to receivers and was contributing to domain-reputation
throttling (Microsoft 451 4.7.500, Gmail low-reputation).
Removed from /etc/postfix/master.cf: transports yahooslow, out02-04,
out06-20, rehab02-04, HC submission ports 2527/2528, hcout2/hcout3.
Removed from /etc/network/interfaces (+ live ip addr del): host bindings
.90-.93, .95-.106, .108-.109. Kept: .94 (trucking/out05), .107 (HC/hcout1),
.71/.72 (infra).
Verified live: postfix check OK, both streams still status=sent post-change,
SSH session on .71 unaffected, transport_maps still routes via out05.
Snapshots: infra/postfix/live-snapshots/master.cf, infra/network/interfaces.
Live backups on server: /root/{master.cf,interfaces}.bak_snowshoe_*.