matematikfessor.dk

Records from scan: 2026-10-08 22:54:31 · 1030ms total · last checked 2026-10-19 22:56 (unchanged)

⬇ Zone File 📜 Timeline & History ⚡ Scan Now

matematikfessor.dk is a .dk domain served by 2 nameservers (jack.ns.cloudflare.com, rita.ns.cloudflare.com). It was already in the .dk zone when our tracking began on 16 June 2026. Its website address 104.20.43.156 is hosted by Cloudflare, Inc. (AS13335). Mail is handled by aspmx.l.google.com, alt1.aspmx.l.google.com and 5 more. The zone is not DNSSEC-signed, 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 33ms

Nameserver	IP addresses	PTR	ASN / ISP
jack.ns.cloudflare.com	108.162.193.121 172.64.33.121 173.245.59.121 2606:4700:58::adf5:3b79 2803:f800:50::6ca2:c179 2a06:98c1:50::ac40:2179	jack.ns.cloudflare.com jack.ns.cloudflare.com jack.ns.cloudflare.com jack.ns.cloudflare.com jack.ns.cloudflare.com jack.ns.cloudflare.com	AS13335 Cloudflare, Inc. AS13335 Cloudflare, Inc. AS13335 Cloudflare, Inc. AS13335 Cloudflare, Inc. AS13335 Cloudflare, Inc. AS13335 Cloudflare, Inc.
rita.ns.cloudflare.com	108.162.192.140 172.64.32.140 173.245.58.140 2606:4700:50::adf5:3a8c 2803:f800:50::6ca2:c08c 2a06:98c1:50::ac40:208c	rita.ns.cloudflare.com rita.ns.cloudflare.com rita.ns.cloudflare.com rita.ns.cloudflare.com rita.ns.cloudflare.com rita.ns.cloudflare.com	AS13335 Cloudflare, Inc. AS13335 Cloudflare, Inc. AS13335 Cloudflare, Inc. AS13335 Cloudflare, Inc. AS13335 Cloudflare, Inc. AS13335 Cloudflare, Inc.

🌍 A Records#

2 records 33ms

IP	TTL	PTR	ASN	ISP / Org	CIDR	Country	City
104.20.43.156	300s	—	AS13335	Cloudflare, Inc.	104.20.0.0/18	—	—
172.66.168.148	300s	—	AS13335	Cloudflare, Inc.	172.66.160.0/20	—	—

📧 MX Records#

7 records 35ms

Priority	TTL	Mail Server	IP addresses	PTR	ASN
10	300s	aspmx.l.google.com	108.177.14.27 2a00:1450:4010:c03::1a 2a00:1450:4010:c03::1a	lt-in-f27.1e100.net lr-in-x1a.1e100.net lr-in-f26.1e100.net	AS15169 Google LLC AS15169 Google LLC AS15169 Google LLC
20	300s	alt1.aspmx.l.google.com	192.178.158.26 2404:6800:4013:813::1a	lcdels-in-f26.1e100.net lcdels-in-f26.1e100.net	AS15169 Google LLC AS15169 Google LLC
20	300s	alt2.aspmx.l.google.com	173.194.41.27 173.194.41.27 2404:6800:4001:c01::1a	yukulwh-in-f27.1e100.net mad01s14-in-f27.1e100.net yukulwh-in-f26.1e100.net	AS15169 Google LLC AS15169 Google LLC AS15169 Google LLC
30	300s	aspmx2.googlemail.com	192.178.158.26 2404:6800:4013:813::1a	lcdels-in-f26.1e100.net lcdels-in-f26.1e100.net	AS15169 Google LLC AS15169 Google LLC
30	300s	aspmx3.googlemail.com	173.194.41.27 173.194.41.27 2404:6800:4001:c01::1b	yukulwh-in-f27.1e100.net mad01s14-in-f27.1e100.net yukulwh-in-f27.1e100.net	AS15169 Google LLC AS15169 Google LLC AS15169 Google LLC
30	300s	aspmx4.googlemail.com	172.253.158.27 2404:6800:4003:c26::1b	so-in-f27.1e100.net so-in-f27.1e100.net	AS15169 Google LLC AS15169 Google LLC
30	300s	aspmx5.googlemail.com	108.177.125.26 2404:6800:4008:c01::1b	tp-in-f26.1e100.net tp-in-f27.1e100.net	AS15169 Google LLC AS15169 Google LLC

🔷 AAAA Records (IPv6)#

✗ No AAAA records — IPv6 not configured

🔐 HTTPS Records#

1 records 42ms

Priority	Target	SvcParams
1 service	.	alpn="h2" ipv4hint=104.20.43.156,172.66.168.148

📝 TXT Records#

6 records 168ms

TXT Record
_bfcxrdfdx2i7moruqop6fcbsrosf43z
ahrefs-site-verification_1ad5148ad0b4b45fd747bb95c0abbb1804c6a56c42aee85ec8ec164e098d05b8
google-site-verification=DGwLEquGMDhgdAMrLYO4CBvay3h-1sUqtzMAwIKon5M
google-site-verification=jgp9kySin-Wc_1sBUTcsRJN5dDJ_p6Swv12i0f48iK4
itk9l3bo0tkunqtq8b6f6bh12i
v=spf1 include:spf.dixa.io include:_spf.google.com include:spf.mandrillapp.com ~all

✉️ SPF#

Policy	Record (matematikfessor.dk)
~all (soft fail)	v=spf1 include:spf.dixa.io include:_spf.google.com include:spf.mandrillapp.com ~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 2026-10-08 22:54:31

www	104.20.43.156 172.66.168.148 (AS13335) (address records, no CNAME)
www vs bare domain	Same network matematikfessor.dk: 104.20.43.156 172.66.168.148 (AS13335) www.matematikfessor.dk: 104.20.43.156 172.66.168.148 (AS13335)
Wildcard	No

✍️ DKIM keys#

2 found

Selector	CNAME	Key
s1	s1.domainkey.u18921011.wl012.sendgrid.net	RSA · ~2048 bit
s2	s2.domainkey.u18921011.wl012.sendgrid.net	RSA · ~1024 bit below 2048 bit

DKIM selectors can't be listed, so we check the common ones (Microsoft 365, Google, Mailchimp, SendGrid, generic). Keys under other selectors aren't shown.

🔎 SPF check#

zone-wide SPF report

DNS lookups: 4/10 · policy: ~all

No problems found

🔗 TLSA / DANE#

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

🔐 DNSSEC#

63ms

Check	Result
Validation Status	🔓 Insecure
AD Flag (resolver validates)	✗ Not set
DS Record	✗ Not found
DNSKEY Record	✗ Not found
Flags	unsigned answer

🏷️ SOA#

39ms

Field	Value
Serial	2414084864
Primary NS (MNAME)	jack.ns.cloudflare.com
Responsible (RNAME)	dns@cloudflare.com
Refresh	10000s
Retry	2400s
Expire	604800s
Minimum (neg-cache TTL)	1800s

📋 Registration#

✗ No registration data yet — queued for a WHOIS lookup

📋 WHOIS#

⏱️ Lookup Timing#

33ms

35ms

AAAA

31ms

TXT

168ms

CAA

32ms

HTTPS

42ms

TLSA

73ms

SOA

39ms

MTA-STS

47ms

DNSSEC

63ms

SRV

58ms

Total

1030ms

🕐 Scan History#

Scanned At	Duration	Records	DNSSEC
2026-10-08 22:54:31 shown	1030ms	2 NS 2 A 7 MX	🔓 Insecure
2026-09-07 14:30:35	4148ms	2 NS 2 A 7 MX	🔓 Insecure
2026-08-29 08:42:23	1609ms	2 NS 2 A 7 MX	🔓 Insecure
2026-08-26 13:19:00	1176ms	2 NS 2 A 7 MX	🔓 Insecure
2026-07-08 20:52:38	1908ms	2 NS 2 A 7 MX	🔓 Insecure
2026-06-24 17:25:18	1141ms	2 NS 2 A 7 MX	🔓 Insecure
2026-06-23 21:56:21	1170ms	0 NS 0 A 0 MX	❓ Unknown
2026-06-18 02:17:05	961ms	2 NS 2 A 7 MX	🔓 Insecure