blue52.dk is a .dk domain served by 3 nameservers (ns1.e-studio.dk, ns2.e-studio.dk, ns3.e-studio.dk). It was registered on 15 February 2022 (WHOIS) and was already in the .dk zone when our tracking began on 16 June 2026. Mail is handled by mx4.spamfri.dk, mx2.spamfri.dk and 2 more. The zone is not DNSSEC-signed, has no 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 |
|---|---|---|---|
| ns1.e-studio.dk | — | — | — |
| ns2.e-studio.dk | — | — | — |
| ns3.e-studio.dk | — | — | — |
| IP | TTL | PTR | ASN | ISP / Org | CIDR | Country | City |
|---|---|---|---|---|---|---|---|
| 193.200.90.180 | — | web8.e-studio.dk | AS62121 | — | — | — | — |
| Priority | TTL | Mail Server | IP addresses | PTR | ASN |
|---|---|---|---|---|---|
| 10 | — | mx4.spamfri.dk | 193.200.91.108 | mx4.spamfri.dk | AS62121 Christian Ebsen ApS |
| 20 | — | mx2.spamfri.dk | 193.200.91.109 | mx2.spamfri.dk | AS62121 Christian Ebsen ApS |
| 30 | — | mx3.spamfri.dk | 62.69.152.43 62.69.152.43 |
43.34-46.152.69.62.in-addr.arpa mx3.spamfri.dk |
AS47527 DLX A/S AS47527 DLX A/S |
| 40 | — | mx1.spamfri.dk | 195.242.131.16 | mx1.spamfri.dk | AS62121 Christian Ebsen ApS |
| TXT Record |
|---|
| v=spf1 include:_spf.e-studio.dk -all |
| Policy | Record (blue52.dk) |
|---|---|
| -all (hard fail) | v=spf1 include:_spf.e-studio.dk -all |
| www CNAME | blue52.dk (all on blue52.dk) |
| www vs bare domain | Same network |
| Wildcard | No |
| Denial of existence | NSEC3 · 7 iterations · 8-byte salt RFC 9276 recommends 0 iterations and no salt |
| CDS / CDNSKEY | None 0 CDS, 0 CDNSKEY |
| Selector | CNAME | Key |
|---|---|---|
| default | — | 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.mx1.spamfri.dk | DANE-EE · SPKI · SHA-256 | 884451547A03D0AC2F628D943839BAA6… |
| SMTP _25._tcp.mx2.spamfri.dk | DANE-EE · SPKI · SHA-256 | 6598C93F79B95376BB8099E9AC862167… |
| SMTP _25._tcp.mx3.spamfri.dk | DANE-EE · SPKI · SHA-256 | BBFB0694919290E5BC9D6E2C6F47D846… |
| SMTP _25._tcp.mx4.spamfri.dk | DANE-EE · SPKI · SHA-256 | 4EE743A99328AEF5142706CA5FD3AD61… |
| Check | Result |
|---|---|
| Validation Status | 🔓 Insecure |
| AD Flag (resolver validates) | ✗ Not set |
| DS Record | ✗ Not found |
| DNSKEY Record | ✓ Found |
| Flags | unsigned answer |
| Field | Value |
|---|---|
| Serial | 2026052101 |
| Primary NS (MNAME) | ns1.e-studio.dk |
| Responsible (RNAME) | hostmaster@mailrelay.e-studio.dk |
| Refresh | 3600s |
| Retry | 1800s |
| Expire | 1209600s |
| Minimum (neg-cache TTL) | 86400s |
| Field | Value |
|---|---|
| Registrar | Punktum dk A/S (direct) |
| Registered | 2022-02-15 |
| Expires | 2028-02-14 (485d) |
| Scanned At | Duration | Records | DNSSEC |
|---|---|---|---|
| 2026-09-30 13:52:03 | 683ms | 3 NS 1 A 4 MX | 🔓 Insecure |
| 2026-09-29 20:47:48 | 581ms | 3 NS 1 A 4 MX | 🔓 Insecure |
| 2026-09-26 06:19:45 | 656ms | 3 NS 1 A 4 MX | 🔓 Insecure |
| 2026-09-21 09:34:13 | 1391ms | 3 NS 1 A 4 MX | 🔓 Insecure |
| 2026-07-21 19:15:01 | 1235ms | 3 NS 1 A 4 MX | 🔓 Insecure |
| 2026-07-01 23:26:21 | 868ms | 3 NS 1 A 4 MX | 🔓 Insecure |
| 2026-06-16 15:09:23 | 496ms | 3 NS 1 A 4 MX | 🔓 Insecure |
| 2026-06-16 15:08:49 shown | 2934ms | 3 NS 1 A 4 MX | 🔓 Insecure |
| 2026-06-16 15:06:58 | 2366ms | 3 NS 1 A 4 MX | 🔓 Insecure |
| 2026-06-16 15:01:06 | 703ms | 3 NS 1 A 4 MX | 🔓 Insecure |