cstp.dk is a .dk domain served by 2 nameservers (ns01.one.com, ns02.one.com). It was registered on 29 January 2013 (WHOIS) and was already in the .dk zone when our tracking began on 16 June 2026. Mail is handled by mail.tutanota.de. The zone is DNSSEC-signed but currently fails validation, publishes a DMARC policy and has no IPv6 address. 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.
| Nameserver | IP addresses | PTR | ASN / ISP |
|---|---|---|---|
| ns01.one.com | — | — | — |
| ns02.one.com | — | — | — |
| Priority | TTL | Mail Server | IP addresses | PTR | ASN |
|---|---|---|---|---|---|
| 1 | — | mail.tutanota.de | 185.205.69.211 185.205.69.213 185.205.69.214 |
mail.w11.tutanota.de mail.w13.tutanota.de mail.w14.tutanota.de |
AS210909 Tutao GmbH AS210909 Tutao GmbH AS210909 Tutao GmbH |
| TXT Record |
|---|
| t-verify=1a176b337f972bbb69280754f8f57c95 |
| v=spf1 include:spf.tutanota.de -all |
| Policy | Record (cstp.dk) |
|---|---|
| -all (hard fail) | v=spf1 include:spf.tutanota.de -all |
| Policy | Record (_dmarc.cstp.dk) |
|---|---|
| p=quarantine | v=DMARC1; p=quarantine; adkim=s |
| Check | Result |
|---|---|
| Status | 🔒 Enforce |
| TXT record (_mta-sts) | ✓ Found |
| HTTPS policy | ✓ Valid |
| Mode | enforce |
| Policy ID | 20190723 |
| max_age | 86400s |
| Policy MX | — |
| www | 46.30.211.38 (AS51468) (address records, no CNAME) |
| www vs bare domain | Only www resolves (all like this) |
| Wildcard | No |
| Denial of existence | NSEC3 · 0 iterations · no salt RFC 9276 ✓ |
| CDS / CDNSKEY | None 0 CDS, 0 CDNSKEY |
| Selector | CNAME | Key |
|---|---|---|
| s1 | s1.domainkey.tutanota.de | RSA · ~2048 bit |
| s2 | s2.domainkey.tutanota.de | RSA · ~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.
DNS lookups: 1/10 · policy: -all
No problems found| Service / Owner | Type | Cert association |
|---|---|---|
| SMTP _25._tcp.mail.tutanota.de | DANE-EE · Full cert · SHA-256 | D141F8F3A4AAC2E4D2677AAFCC723D8E… |
| Check | Result |
|---|---|
| Validation Status | ⚠️ Bogus |
| AD Flag (resolver validates) | ✗ Not set |
| DS Record | ✓ Found |
| DNSKEY Record | ✓ Found |
| Flags | resolution failed: failure |
| Field | Value |
|---|---|
| Serial | 2026061201 |
| Primary NS (MNAME) | ns01.one.com |
| Responsible (RNAME) | hostmaster@one.com |
| Refresh | 14400s |
| Retry | 3600s |
| Expire | 1209600s |
| Minimum (neg-cache TTL) | 600s |
| Field | Value |
|---|---|
| Registrar | Punktum dk A/S (direct) |
| Registered | 2013-01-29 |
| Expires | 2027-01-31 (99d) |
| Scanned At | Duration | Records | DNSSEC |
|---|---|---|---|
| 2026-10-23 21:09:03 | 731ms | 2 NS 0 A 1 MX | 🔒 Secure |
| 2026-10-12 18:24:58 | 1593ms | 2 NS 0 A 1 MX | 🔒 Secure |
| 2026-10-09 10:22:49 | 749ms | 2 NS 0 A 1 MX | 🔒 Secure |
| 2026-09-30 14:56:10 | 590ms | 2 NS 0 A 1 MX | 🔒 Secure |
| 2026-09-30 08:10:41 | 681ms | 2 NS 0 A 1 MX | 🔒 Secure |
| 2026-09-23 15:36:55 | 679ms | 2 NS 0 A 1 MX | 🔒 Secure |
| 2026-09-11 15:32:23 | 986ms | 2 NS 0 A 1 MX | 🔒 Secure |
| 2026-09-04 13:39:05 | 650ms | 2 NS 0 A 1 MX | 🔒 Secure |
| 2026-08-31 11:26:17 | 750ms | 2 NS 0 A 1 MX | 🔒 Secure |
| 2026-08-25 02:38:32 | 2551ms | 2 NS 0 A 1 MX | 🔒 Secure |
| 2026-08-12 18:40:58 | 3087ms | 2 NS 0 A 1 MX | 🔒 Secure |
| 2026-07-19 00:47:46 | 862ms | 2 NS 0 A 1 MX | 🔒 Secure |
| 2026-07-13 14:06:48 | 994ms | 2 NS 0 A 1 MX | 🔒 Secure |
| 2026-06-22 05:44:43 | 799ms | 2 NS 0 A 1 MX | 🔒 Secure |
| 2026-06-16 23:06:01 shown | 707ms | 2 NS 0 A 1 MX | ⚠️ Bogus |