strfisk.dk is a .dk domain served by 3 nameservers (ns1.simply.com, ns2.simply.com, ns3.simply.com). It was registered on 7 September 2011 (WHOIS) and was already in the .dk zone when our tracking began on 16 June 2026. Its website address 51.144.135.21 is hosted by Microsoft Corporation (AS8075) in The Netherlands. Mail is handled by strfisk-dk.mail.protection.outlook.com, mx.simply.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 this scan: nameservers, A/AAAA, MX, TXT, SPF, DMARC, CAA, TLSA/DANE, MTA-STS, SRV and more.
| IP | TTL | PTR | ASN | ISP / Org | CIDR | Country | City |
|---|---|---|---|---|---|---|---|
| 51.144.135.21 | — | — | AS8075 | Microsoft Corporation | 51.144.0.0/15 | 🇳🇱 The Netherlands | Amsterdam |
| TXT Record |
|---|
| MS=ms17339131 |
| v=spf1 include:spf.protection.outlook.com include:web.shared.mysmtp.com include:_spf.smtp.com ~all |
| Policy | Record (strfisk.dk) |
|---|---|
| ~all (soft fail) | v=spf1 include:spf.protection.outlook.com include:web.shared.mysmtp.com include:_spf.smtp.com ~all |
| www | 51.144.135.21 (AS8075) (address records, no CNAME) |
| www vs bare domain | Same network |
| Wildcard | No |
| Denial of existence | NSEC zone can be walked (all names enumerable) |
| CDS / CDNSKEY | Published: key rollovers can be automated with the registry (RFC 7344/8078) 1 CDS, 1 CDNSKEY |
| Selector | CNAME | Key |
|---|---|---|
| selector1 | selector1-strfisk-dk._domainkey.strfisk.q-v1.dkim.mail.microsoft | RSA · ~2048 bit |
| selector2 | selector2-strfisk-dk._domainkey.strfisk.q-v1.dkim.mail.microsoft | 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: 6/10 · policy: ~all
No problems found| Service / Owner | Type | Cert association |
|---|---|---|
| SMTP _25._tcp.mx.simply.com | DANE-EE · SPKI · SHA-256 | A9D603AF4D7ED6B9246B4B68500CD6F2… |
| SMTP _25._tcp.mx.simply.com | DANE-EE · SPKI · SHA-256 | 97A3BA009F39C761BFFB6574340E8138… |
| Check | Result |
|---|---|
| Validation Status | 🔒 Secure |
| AD Flag (resolver validates) | ✓ Set |
| DS Record | ✓ Found |
| DNSKEY Record | ✓ Found |
| Flags | fully validated |
| Field | Value |
|---|---|
| Serial | 2025072300 |
| Primary NS (MNAME) | ns1.simply.com |
| Responsible (RNAME) | hostmaster@simply.com |
| Refresh | 14400s |
| Retry | 3600s |
| Expire | 1209600s |
| Minimum (neg-cache TTL) | 3600s |
| Field | Value |
|---|---|
| Registrar | Simply.com A/S |
| Registered | 2011-09-07 |
| Expires | 2027-09-30 (343d) |
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).
No other domain with this registrant in our WHOIS data yet| Scanned At | Duration | Records | DNSSEC |
|---|---|---|---|
| 2026-10-14 09:06:19 | 1755ms | 3 NS 1 A 1 MX | 🔒 Secure |
| 2026-10-09 01:57:29 | 1084ms | 3 NS 1 A 1 MX | 🔒 Secure |
| 2026-10-07 08:37:37 | 1983ms | 3 NS 1 A 1 MX | 🔒 Secure |
| 2026-10-01 03:57:40 | 840ms | 3 NS 1 A 1 MX | 🔒 Secure |
| 2026-09-30 03:49:49 | 1513ms | 3 NS 1 A 1 MX | 🔒 Secure |
| 2026-08-27 22:01:21 | 1200ms | 3 NS 1 A 2 MX | 🔒 Secure |
| 2026-06-25 09:29:40 | 2557ms | 3 NS 1 A 2 MX | 🔒 Secure |
| 2026-06-23 14:32:15 | 943ms | 3 NS 1 A 2 MX | 🔒 Secure |
| 2026-06-22 10:36:05 | 1313ms | 3 NS 1 A 2 MX | 🔒 Secure |
| 2026-06-19 21:25:16 | 610ms | 3 NS 1 A 2 MX | 🔒 Secure |
| 2026-06-17 14:01:40 shown | 2292ms | 3 NS 1 A 2 MX | 🔒 Secure |