rfsu.dk is a .dk domain served by 2 nameservers (dns-b.buildit.net, dns-c.buildit.eu). It was registered on 9 October 2002 (WHOIS) and was already in the .dk zone when our tracking began on 16 June 2026. Its website address 213.88.149.101 is hosted by Tele2 SWIPnet (AS1257) in Sweden. Mail is handled by rfsu-dk.mail.protection.outlook.com. The zone is not DNSSEC-signed, 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.
| IP | TTL | PTR | ASN | ISP / Org | CIDR | Country | City |
|---|---|---|---|---|---|---|---|
| 213.88.149.101 | 3600s | rfsu25.bldt.dev | AS1257 | Tele2 SWIPnet | 213.88.128.0/17 | 🇸🇪 Sweden | Mariestad |
| Service | CNAME / IP |
|---|---|
| 🔷 Autodiscover | autodiscover.outlook.com → 40.104.116.24 |
| TXT Record |
|---|
| MS=ms48811067 |
| v=spf1 include:spf.protection.outlook.com include:spf.eu.exclaimer.net -all |
| Policy | Record (rfsu.dk) |
|---|---|
| -all (hard fail) | v=spf1 include:spf.protection.outlook.com include:spf.eu.exclaimer.net -all |
| Policy | Record (_dmarc.rfsu.dk) |
|---|---|
| p=reject | v=DMARC1;p=reject;sp=reject;adkim=s;aspf=s |
| www CNAME | rfsu.dk (all on rfsu.dk) → 213.88.149.101 (AS1257) |
| www vs bare domain | Same network |
| Wildcard | No |
| Selector | CNAME | Key |
|---|---|---|
| selector1 | selector1-rfsu-dk._domainkey.rfsu.onmicrosoft.com | RSA · ~2048 bit |
| selector2 | selector2-rfsu-dk._domainkey.rfsu.onmicrosoft.com | 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: 2/10 · policy: -all
No problems found| Check | Result |
|---|---|
| Validation Status | 🔓 Insecure |
| AD Flag (resolver validates) | ✗ Not set |
| DS Record | ✗ Not found |
| DNSKEY Record | ✗ Not found |
| Flags | unsigned answer |
| Field | Value |
|---|---|
| Serial | 2026012202 |
| Primary NS (MNAME) | dns-b.buildit.net |
| Responsible (RNAME) | hostmaster@buildit.net |
| Refresh | 28800s |
| Retry | 7200s |
| Expire | 604800s |
| Minimum (neg-cache TTL) | 7200s |
| Field | Value |
|---|---|
| Registrar | NETIM |
| Registered | 2002-10-09 |
| Expires | 2026-12-31 (73d) |
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).
| Domain | Registrar |
|---|---|
| rfsushop.dk | NETIM |
| Scanned At | Duration | Records | DNSSEC |
|---|---|---|---|
| 2026-10-12 16:12:24 | 2328ms | 2 NS 1 A 1 MX | 🔓 Insecure |
| 2026-10-09 12:14:44 | 1681ms | 2 NS 1 A 1 MX | 🔓 Insecure |
| 2026-10-04 04:54:06 | 1253ms | 2 NS 1 A 1 MX | 🔓 Insecure |
| 2026-10-01 04:26:27 shown | 1470ms | 2 NS 1 A 1 MX | 🔓 Insecure |
| 2026-06-25 23:24:49 | 1194ms | 2 NS 1 A 1 MX | 🔓 Insecure |
| 2026-06-24 08:12:48 | 3561ms | 2 NS 1 A 1 MX | ❓ Unknown |
| 2026-06-21 23:09:40 | 900ms | 0 NS 0 A 0 MX | ❓ Unknown |
| 2026-06-21 17:30:49 | 925ms | 0 NS 0 A 0 MX | ❓ Unknown |
| 2026-06-18 05:52:48 | 959ms | 2 NS 1 A 1 MX | 🔓 Insecure |