Add parked domain CSV helper

README.md

@@ -74,6 +74,23 @@ The generated CSV includes the following columns:
 - Redirect Chain
 - HTTP Error
 
+## Parked Domain CSV Generator
+
+The `scripts/parked_domain_csv.py` helper script creates DNS change records for
+locking down parked or non-mailing domains. Provide a text file of domains and
+an output CSV path:
+
+```bash
+python scripts/parked_domain_csv.py domains.txt parked_domains.csv
+```
+
+Each domain receives the following DNS entries:
+
+- SPF record with `-all`
+- Null MX record
+- DKIM wildcard with an empty key
+- DMARC CNAME pointing to a reject policy
+
 ## License
 
 This project is released under the MIT License. See [LICENSE](LICENSE) for details.

scripts/parked_domain_csv.py

@@ -0,0 +1,58 @@
+import csv
+import sys
+
+HEADER = [
+    "Action",
+    "Zone",
+    "Record Name",
+    "Record Type",
+    "TTL",
+    "Value",
+    "Comments",
+]
+
+RECORD_TEMPLATE = [
+    ["REMOVE", "{domain}", "@", "MX", "", "10 custmx.cscdns.net.", "Remove existing MX record"],
+    ["ADD", "{domain}", "@", "TXT", "3600", "v=spf1 -all", "SPF hard fail"],
+    ["ADD", "{domain}", "@", "MX", "3600", "0 .", "Null MX (RFC 7505)"],
+    ["ADD", "{domain}", "*._domainkey", "TXT", "3600", "v=DKIM1; p=", "DKIM wildcard with empty key"],
+    ["ADD", "{domain}", "_dmarc", "CNAME", "3600", "reject.dmarc.fabrikam.com.", "DMARC reject policy via CNAME"],
+]
+
+
+def generate_records(domain: str):
+    records = [[f"--- {domain} ---", "", "", "", "", "", "Domain configuration"]]
+    for template in RECORD_TEMPLATE:
+        records.append([
+            template[0],
+            domain,
+            template[2],
+            template[3],
+            template[4],
+            template[5],
+            template[6],
+        ])
+    return records
+
+
+def main():
+    if len(sys.argv) != 3:
+        print("Usage: python parked_domain_csv.py domains.txt output.csv")
+        sys.exit(1)
+
+    domain_file = sys.argv[1]
+    output_csv = sys.argv[2]
+
+    with open(domain_file, "r", encoding="utf-8") as f:
+        domains = [line.strip() for line in f if line.strip()]
+
+    with open(output_csv, "w", newline="", encoding="utf-8") as csvfile:
+        writer = csv.writer(csvfile)
+        writer.writerow(HEADER)
+        for domain in domains:
+            for row in generate_records(domain):
+                writer.writerow(row)
+
+
+if __name__ == "__main__":
+    main()