holtbyg.dk

Records from scan: 2026-10-07 22:14:11 · 1140ms total · last checked 2026-10-23 21:08 (unchanged)

⬇ Zone File 📜 Timeline & History ⚡ Scan Now

holtbyg.dk is a .dk domain served by 2 nameservers (ns1.curanet.dk, ns2.curanet.dk). It was registered on 18 August 2005 (WHOIS) and was already in the .dk zone when our tracking began on 16 June 2026. Its website address 185.21.40.221 is hosted by team.blue Denmark A/S (AS48854) in Denmark. Mail is handled by holtbyg-dk.mail.protection.outlook.com. The zone is DNSSEC-signed and validates, has no DMARC policy and has no IPv6 address. Below are all of its DNS records from our latest scan: nameservers, A/AAAA, MX, TXT, SPF, DMARC, CAA, TLSA/DANE, MTA-STS, SRV and more.

🖥️ Nameservers#

2 records 42ms

Nameserver	IP addresses	PTR	ASN / ISP
ns1.curanet.dk	185.25.141.12 2a02:2339:4006:108::123	ns1.curanet.dk ns1.curanet.dk	AS48854 team.blue Denmark A/S AS48854 team.blue Denmark A/S
ns2.curanet.dk	2a02:2339:1:10f::123:123 91.197.248.75	ns2.curanet.dk ns2.curanet.dk	AS48854 team.blue Denmark A/S AS48854 team.blue Denmark A/S

🌍 A Records#

1 records 36ms

IP	TTL	PTR	ASN	ISP / Org	CIDR	Country	City
185.21.40.221	3600s	vm1212.enterprisecloud.nu	AS48854	team.blue Denmark A/S	185.21.40.0/22	🇩🇰 Denmark	—

📧 MX Records#

1 records 43ms

Priority	TTL	Mail Server	IP addresses	PTR	ASN
10	3600s	holtbyg-dk.mail.protection.outlook.com	2a01:111:f403:ca04::d 2a01:111:f403:ca21::10 2a01:111:f403:ca21::a 2a01:111:f403:ca21::c 52.101.68.12 52.101.73.120 52.101.73.153 52.101.91.162	mail-db6pr03cu00105.inbound.protection.outlook.com mail-matpr05cu00100.inbound.protection.outlook.com mail-maspr04cu00102.inbound.protection.outlook.com mail-matpr04cu00204.inbound.protection.outlook.com mail-db9pr02cu00204.inbound.protection.outlook.com mail-am7pr02cu00300.inbound.protection.outlook.com mail-as8pr05cu00401.inbound.protection.outlook.com mail-matpr04cu00302.inbound.protection.outlook.com	AS8075 Microsoft Corporation AS8075 Microsoft Corporation AS8075 Microsoft Corporation AS8075 Microsoft Corporation AS8075 Microsoft Corporation AS8075 Microsoft Corporation AS8075 Microsoft Corporation AS8075 Microsoft Corporation

📧 Autodiscover / Autoconfig#

Service	CNAME / IP
🔷 Autodiscover	autodiscover.outlook.com → 52.98.154.152

🔷 AAAA Records (IPv6)#

✗ No AAAA records — IPv6 not configured

🔐 HTTPS Records#

✗ No HTTPS RR — no SVCB/HTTPS service binding

📝 TXT Records#

2 records 115ms

TXT Record
MS=ms84491314
v=spf1 include:spf.curanet.dk include:web.shared.mysmtp.com include:spf.protection.outlook.com include:amazonses.com include:spf.surf-town.net ~all

✉️ SPF#

Policy	Record (holtbyg.dk)
~all (soft fail)	v=spf1 include:spf.curanet.dk include:web.shared.mysmtp.com include:spf.protection.outlook.com include:amazonses.com include:spf.surf-town.net ~all

📨 DMARC#

✗ No DMARC record — mail spoofing not restricted

📬 MTA-STS#

✗ No MTA-STS policy — SMTP TLS not enforced

📈 TLSRPT#

✗ No TLSRPT record — no SMTP TLS failure reporting

📜 CAA Records#

✗ No CAA records — any CA may issue certificates

🧩 Web & zone#

checked 2026-10-07 22:14:11

www	185.21.40.221 (AS48854) (address records, no CNAME)
www vs bare domain	Same network holtbyg.dk: 185.21.40.221 (AS48854) www.holtbyg.dk: 185.21.40.221 (AS48854)
Wildcard	No
Denial of existence	NSEC3 · 1 iteration · 1-byte salt RFC 9276 recommends 0 iterations and no salt
CDS / CDNSKEY	None 0 CDS, 0 CDNSKEY

🔎 SPF check#

zone-wide SPF report

DNS lookups: 13/10 · policy: ~all

error include:smtp-mail-spf.surftown.com has no SPF record: receivers that reach it return permerror (RFC 7208 §5.2)
error 13 DNS lookups: the limit is 10, so a receiver whose evaluation gets past the 10th returns permerror (SPF fails)

🔗 TLSA / DANE#

✗ No TLSA records — DANE not configured for HTTPS (_443) or MX (_25)

🔐 DNSSEC#

62ms

Check	Result
Validation Status	🔒 Secure
AD Flag (resolver validates)	✓ Set
DS Record	✓ Found
DNSKEY Record	✓ Found
Flags	fully validated

🏷️ SOA#

41ms

Field	Value
Serial	2023061501
Primary NS (MNAME)	ns1.curanet.dk
Responsible (RNAME)	hostmaster@curanet.dk
Refresh	14400s
Retry	3600s
Expire	1209600s
Minimum (neg-cache TTL)	300s

📋 Registration#

WHOIS fetched 2026-10-24 06:33:09

Field	Value
Registrar	CURANET A/S
Registered	2005-08-18
Expires	2027-08-31 (310d)

🔗 Same registrant#

1 domain

Other .dk domains whose WHOIS registrant has the same name and postal address. Matched on a keyed hash: the registrant's details are not stored or shown. Covers only domains whose WHOIS we have fetched (refreshed about monthly).

Domain	Registrar
holt-byg.dk	Punktum dk A/S (direct)

📋 WHOIS#

⏱️ Lookup Timing#

42ms

36ms

43ms

AAAA

36ms

TXT

115ms

CAA

35ms

HTTPS

52ms

TLSA

790ms

SOA

41ms

MTA-STS

43ms

DNSSEC

62ms

SRV

77ms

Total

1140ms

🕐 Scan History#

Scanned At	Duration	Records	DNSSEC
2026-10-07 22:14:11 shown	1140ms	2 NS 1 A 1 MX	🔒 Secure
2026-09-03 04:56:55	784ms	2 NS 1 A 1 MX	🔒 Secure
2026-08-26 05:32:18	1174ms	2 NS 1 A 1 MX	🔒 Secure
2026-06-24 14:06:48	1565ms	2 NS 1 A 1 MX	🔒 Secure
2026-06-23 17:35:17	906ms	0 NS 0 A 0 MX	❓ Unknown
2026-06-19 11:45:13	720ms	2 NS 1 A 1 MX	🔒 Secure
2026-06-17 12:59:30	1842ms	2 NS 1 A 1 MX	🔒 Secure