concreteseal.dk is a .dk domain served by 2 nameservers (ns1.curanet.dk, ns2.curanet.dk). It was already in the .dk zone when our tracking began on 16 June 2026. Its website address 185.21.41.85 is hosted by team.blue Denmark A/S (AS48854) in Denmark. Mail is handled by mx1.onlinemail.io, mx2.onlinemail.io. The zone is DNSSEC-signed and validates, has no DMARC policy and has no IPv6 address. Below are all of its DNS records from our latest 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 |
|---|---|---|---|---|---|---|---|
| 185.21.41.85 | 3600s | linux34.curanet.dk | AS48854 | team.blue Denmark A/S | 185.21.40.0/22 | 🇩🇰 Denmark | — |
| Priority | TTL | Mail Server | IP addresses | PTR | ASN |
|---|---|---|---|---|---|
| 10 | 3600s | mx1.onlinemail.io | 185.21.42.12 | mx1.onlinemail.io | AS48854 team.blue Denmark A/S |
| 20 | 3600s | mx2.onlinemail.io | 46.36.208.16 | mx2.onlinemail.io | AS48854 team.blue Denmark A/S |
| Service | CNAME / IP |
|---|---|
| 🔷 Autodiscover | autodiscover-mf.onlinemail.io → 185.21.40.62 |
| 🔶 Autoconfig | autoconfig-mf.onlinemail.io → 185.21.40.62 |
| TXT Record |
|---|
| v=spf1 include:spf.onlinemail.io -all |
| Policy | Record (concreteseal.dk) |
|---|---|
| -all (hard fail) | v=spf1 include:spf.onlinemail.io -all |
| www | 185.21.41.85 (AS48854) (address records, no CNAME) |
| www vs bare domain | Same network |
| Wildcard | Yes: any name under the zone resolves |
| Denial of existence | NSEC3 · 1 iteration · 1-byte salt RFC 9276 recommends 0 iterations and no salt |
| CDS / CDNSKEY | None 0 CDS, 0 CDNSKEY |
DNS lookups: 3/10 · policy: -all
No problems found| Check | Result |
|---|---|
| Validation Status | 🔒 Secure |
| AD Flag (resolver validates) | ✓ Set |
| DS Record | ✓ Found |
| DNSKEY Record | ✓ Found |
| Flags | fully validated |
| Field | Value |
|---|---|
| Serial | 2023121801 |
| Primary NS (MNAME) | ns1.curanet.dk |
| Responsible (RNAME) | hostmaster@curanet.dk |
| Refresh | 14400s |
| Retry | 3600s |
| Expire | 1209600s |
| Minimum (neg-cache TTL) | 300s |
| Scanned At | Duration | Records | DNSSEC |
|---|---|---|---|
| 2026-10-08 07:30:46 shown | 423ms | 2 NS 1 A 2 MX | 🔒 Secure |
| 2026-09-30 14:32:23 | 550ms | 2 NS 1 A 2 MX | 🔒 Secure |
| 2026-09-25 16:27:34 | 576ms | 2 NS 1 A 2 MX | 🔒 Secure |
| 2026-09-01 19:56:32 | 485ms | 2 NS 1 A 2 MX | 🔒 Secure |
| 2026-08-15 10:06:26 | 32814ms | 2 NS 1 A 2 MX | 🔒 Secure |
| 2026-07-01 13:06:16 | 538ms | 2 NS 1 A 2 MX | 🔒 Secure |
| 2026-06-19 16:50:00 | 576ms | 2 NS 1 A 2 MX | 🔒 Secure |
| 2026-06-17 00:13:22 | 65535ms | 2 NS 1 A 2 MX | 🔒 Secure |
| 2026-06-16 22:02:55 | 411ms | 2 NS 1 A 2 MX | 🔒 Secure |
| 2026-06-16 22:02:19 | 1666ms | 2 NS 1 A 2 MX | 🔒 Secure |
| 2026-06-16 22:00:49 | 2565ms | 2 NS 1 A 2 MX | 🔒 Secure |