Kinds of lists#
- Spam and mail-abuse lists (DNSBLs), mostly relevant to port 25, which proxy networks block anyway.
- Proxy and VPN detection lists that flag hosting ranges and known gateway addresses.
- Threat-intelligence feeds built from attack telemetry, refreshed hourly.
- Site-specific denylists kept by a single target from its own experience.
Checking an address#
Several public lookup services aggregate the main lists; check a dedicated address when it starts drawing challenges, and ask for a replacement if it is listed through no fault of yours.
How it works at ProxShift#
ProxShift screens datacenter ranges for blocklist hits before they reach an order and replaces dedicated addresses that stay unusable; port 25 is blocked on every network so exits never earn mail-abuse listings.