semester.dk

📜 Historical scan 2026-09-29 16:46:35 · ← Latest scan

⬇ Zone File 📜 Timeline & History ⚡ Scan Now

semester.dk is a .dk domain served by 2 nameservers (kinsley.ns.cloudflare.com, nero.ns.cloudflare.com). It was registered on 21 August 2000 (WHOIS) and was already in the .dk zone when our tracking began on 16 June 2026. Its website address 104.21.50.139 is hosted by Cloudflare, Inc. (AS13335). Mail is handled by mx1.improvmx.com, mx2.improvmx.com. The zone is not DNSSEC-signed, publishes a DMARC policy and is reachable over IPv6. Below are all of its DNS records from this scan: nameservers, A/AAAA, MX, TXT, SPF, DMARC, CAA, TLSA/DANE, MTA-STS, SRV and more.

🖥️ Nameservers#

2 records 34ms

Nameserver	IP addresses	PTR	ASN / ISP
kinsley.ns.cloudflare.com	108.162.194.75 162.159.38.75 172.64.34.75 2606:4700:50::a29f:264b 2803:f800:50::6ca2:c24b 2a06:98c1:50::ac40:224b	kinsley.ns.cloudflare.com kinsley.ns.cloudflare.com kinsley.ns.cloudflare.com kinsley.ns.cloudflare.com kinsley.ns.cloudflare.com kinsley.ns.cloudflare.com	AS13335 Cloudflare, Inc. AS13335 Cloudflare, Inc. AS13335 Cloudflare, Inc. AS13335 Cloudflare, Inc. AS13335 Cloudflare, Inc. AS13335 Cloudflare, Inc.
nero.ns.cloudflare.com	108.162.195.28 162.159.44.28 172.64.35.28 2606:4700:58::a29f:2c1c 2803:f800:50::6ca2:c31c 2a06:98c1:50::ac40:231c	nero.ns.cloudflare.com nero.ns.cloudflare.com nero.ns.cloudflare.com nero.ns.cloudflare.com nero.ns.cloudflare.com nero.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 36ms

IP	TTL	PTR	ASN	ISP / Org	CIDR	Country	City
104.21.50.139	300s	—	AS13335	Cloudflare, Inc.	104.21.0.0/17	—	—
172.67.206.200	300s	—	AS13335	Cloudflare, Inc.	172.67.128.0/17	—	—

📧 MX Records#

2 records 43ms

Priority	TTL	Mail Server	IP addresses	PTR	ASN
10	300s	mx1.improvmx.com	13.37.195.136 15.236.236.160 2a05:d012:412:e201:88aa:e7b9:7a43:12d7 2a05:d012:412:e202:f36:2c1f:1a49:d38a 2a05:d012:412:e203:373a:f51a:4a85:1d25 35.181.18.45	ec2-13-37-195-136.eu-west-3.compute.amazonaws.com ec2-15-236-236-160.eu-west-3.compute.amazonaws.com — — — ec2-35-181-18-45.eu-west-3.compute.amazonaws.com	AS16509 Amazon.com, Inc. AS16509 Amazon.com, Inc. AS16509 Amazon.com, Inc. AS16509 Amazon.com, Inc. AS16509 Amazon.com, Inc. AS16509 Amazon.com, Inc.
20	300s	mx2.improvmx.com	13.36.107.63 13.36.222.39 15.236.61.92 2a05:d012:412:e201:1f6e:f6e4:8fd7:4678 2a05:d012:412:e202:e81e:cc44:3b53:8a3d 2a05:d012:412:e203:7e33:3d9c:28d7:ee20	ec2-13-36-107-63.eu-west-3.compute.amazonaws.com ec2-13-36-222-39.eu-west-3.compute.amazonaws.com ec2-15-236-61-92.eu-west-3.compute.amazonaws.com — — —	AS16509 Amazon.com, Inc. AS16509 Amazon.com, Inc. AS16509 Amazon.com, Inc. AS16509 Amazon.com, Inc. AS16509 Amazon.com, Inc. AS16509 Amazon.com, Inc.

🔷 AAAA Records (IPv6)#

2 records 44ms

IPv6 Address	TTL	PTR	ASN	ISP / Org	CIDR	Country	City
2606:4700:3030::ac43:cec8	300s	—	AS13335	Cloudflare, Inc.	2606:4700:3000:0:0:0:0:0/42	—	—
2606:4700:3033::6815:328b	300s	—	AS13335	Cloudflare, Inc.	2606:4700:3000:0:0:0:0:0/42	—	—

🔐 HTTPS Records#

1 records 32ms

Priority	Target	SvcParams
1 service	.	alpn="h3,h2" ipv4hint=104.21.50.139,172.67.206.200 ech=AEX+DQBBZQAgACAEudK70+QtQBQuisRtaRBEifGNxMANoe/QOzs/lZpiZQAEAAEAAQASY2xvdWRmbGFyZS1lY2guY29tAAA= ipv6hint=2606:4700:3030::ac43:cec8,2606:4700:3033::6815:328b

📝 TXT Records#

2 records 176ms

TXT Record
v=spf1 -all
v=spf1 include:spf.improvmx.com ~all

✉️ SPF#

⚠ Multiple SPF records — RFC 7208 §4.5 violation (receivers must treat this as permerror)

Policy	Record (semester.dk)
-all (hard fail)	v=spf1 -all
~all (soft fail)	v=spf1 include:spf.improvmx.com ~all

📨 DMARC#

Policy	Record (_dmarc.semester.dk)
p=reject	v=DMARC1; p=reject; sp=reject; adkim=s; aspf=s; rua=mailto:45b8ff6fcaaa47c482e023ce5e822019@dmarc-reports.cloudflare.net;

📬 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#

latest probe, not this scan · checked 2026-10-07 19:42:01

www	NXDOMAIN
www vs bare domain	www does not resolve semester.dk: 104.21.50.139 172.67.206.200 2a06:98c1:3120::1 2a06:98c1:3121::1 (AS13335) www.semester.dk: no address (all like this)
Wildcard	No

✍️ DKIM keys#

6 found

Selector	CNAME	Key
default	—	Revoked (empty key)
dkim	—	Revoked (empty key)
k1	—	Revoked (empty key)
mail	—	Revoked (empty key)
s1	—	Revoked (empty key)
s2	—	Revoked (empty key)

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: 0/10 · policy: -all

error 2 SPF records: receivers must treat that as a permanent error (RFC 7208 §4.5)

🔏 ACME Challenge#

Type	Name	Value
TXT	_acme-challenge.semester.dk	U4__q2-YKobSkzIDnsPbp9V8G--PKqnq0z6fQNQ-Nq0
TXT	_acme-challenge.semester.dk	jE3Xw4ph50_nEokRVhTKFopmn2UDCOtKU5dO0pNqNYM

🔗 TLSA / DANE#

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

🔐 DNSSEC#

122ms

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

🏷️ SOA#

0ms

Field	Value
Serial	2416131876
Primary NS (MNAME)	kinsley.ns.cloudflare.com
Responsible (RNAME)	dns@cloudflare.com
Refresh	10000s
Retry	2400s
Expire	604800s
Minimum (neg-cache TTL)	1800s

📋 Registration#

WHOIS fetched 2026-10-04 17:27:36

Field	Value
Registrar	Punktum dk A/S (direct)
Registered	2000-08-21
Expires	2030-09-30 (1441d)

📋 WHOIS#

⏱️ Lookup Timing#

34ms

36ms

43ms

AAAA

44ms

TXT

176ms

CAA

56ms

HTTPS

32ms

TLSA

108ms

SOA

0ms

MTA-STS

52ms

DNSSEC

122ms

SRV

87ms

Total

2012ms

🕐 Scan History#

Scanned At	Duration	Records	DNSSEC
2026-10-04 17:15:57	2277ms	2 NS 2 A 2 MX	🔓 Insecure
2026-09-30 16:54:06	957ms	2 NS 2 A 2 MX	🔓 Insecure
2026-09-29 16:46:35 shown	2012ms	2 NS 2 A 2 MX	🔓 Insecure
2026-09-07 20:55:09	10522ms	2 NS 2 A 2 MX	🔓 Insecure
2026-09-02 04:39:33	2375ms	2 NS 2 A 2 MX	🔓 Insecure
2026-08-28 05:30:33	3697ms	2 NS 2 A 2 MX	🔓 Insecure
2026-08-09 15:08:28	1706ms	2 NS 2 A 2 MX	🔓 Insecure
2026-08-02 17:30:00	1278ms	2 NS 2 A 2 MX	🔓 Insecure
2026-06-21 05:32:36	1643ms	2 NS 2 A 2 MX	🔓 Insecure
2026-06-21 05:14:21	1189ms	0 NS 0 A 0 MX	❓ Unknown
2026-06-20 08:02:25	709ms	2 NS 2 A 2 MX	🔓 Insecure
2026-06-17 13:34:10	972ms	2 NS 2 A 2 MX	🔓 Insecure