firstclassnetworking.dk is a .dk domain served by 4 nameservers (ns1.simply.com, ns2.simply.com, ns3.simply.com and 1 more). It was registered on 18 July 2022 (WHOIS) and was already in the .dk zone when our tracking began on 16 June 2026. Its website address 185.20.205.50 is hosted by team.blue Denmark A/S (AS48854) in Denmark. Mail is handled by firstclassnetworking-dk.mail.protection.outlook.com, mx.simply.com. The zone is DNSSEC-signed and validates, 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 |
|---|---|---|---|
| ns1.simply.com | — | — | — |
| ns2.simply.com | — | — | — |
| ns3.simply.com | — | — | — |
| ns4.simply.com | — | — | — |
| IP | TTL | PTR | ASN | ISP / Org | CIDR | Country | City |
|---|---|---|---|---|---|---|---|
| 185.20.205.50 | — | linux376.unoeuro.com | AS48854 | team.blue Denmark A/S | 185.20.204.0/22 | 🇩🇰 Denmark | — |
| TXT Record |
|---|
| MS=ms45739085 |
| v=spf1 include:spf.protection.outlook.com -all |
| Policy | Record (firstclassnetworking.dk) |
|---|---|
| -all (hard fail) | v=spf1 include:spf.protection.outlook.com -all |
| Policy | Record (_dmarc.firstclassnetworking.dk) |
|---|---|
| p=reject | v=DMARC1; p=reject; rua=mailto:dmarc@robot.simply.com; ruf=mailto:dmarc@robot.simply.com; |
| www | 185.20.205.50 (AS48854) (address records, no CNAME) |
| www vs bare domain | Same network firstclassnetworking.dk: 185.20.205.50 (AS48854) www.firstclassnetworking.dk: 185.20.205.50 (AS48854) |
| Wildcard | Yes: any name under the zone resolves |
| 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 |
|---|---|---|
| s1 | s1.domainkey.u7259658.wl159.sendgrid.net | RSA · ~2048 bit |
| s2 | s2.domainkey.u7259658.wl159.sendgrid.net | RSA · ~1024 bit below 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.mx.simply.com | DANE-EE · SPKI · SHA-256 | 97A3BA009F39C761BFFB6574340E8138… |
| SMTP _25._tcp.mx.simply.com | DANE-EE · SPKI · SHA-256 | A9D603AF4D7ED6B9246B4B68500CD6F2… |
| Check | Result |
|---|---|
| Validation Status | 🔒 Secure |
| AD Flag (resolver validates) | ✓ Set |
| DS Record | ✓ Found |
| DNSKEY Record | ✓ Found |
| Flags | fully validated |
| Field | Value |
|---|---|
| Serial | 2026021000 |
| 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 | Punktum dk A/S (direct) |
| Registered | 2022-07-18 |
| Expires | 2027-07-17 (272d) |
| Scanned At | Duration | Records | DNSSEC |
|---|---|---|---|
| 2026-10-02 08:39:06 | 1092ms | 4 NS 1 A 2 MX | 🔒 Secure |
| 2026-07-24 10:05:01 | 2831ms | 4 NS 1 A 2 MX | 🔒 Secure |
| 2026-07-23 07:56:50 | 654ms | 1 NS 0 A 0 MX | ❓ Unknown |
| 2026-07-22 03:55:43 | 695ms | 1 NS 0 A 0 MX | ❓ Unknown |
| 2026-07-21 03:51:00 | 711ms | 1 NS 0 A 0 MX | ❓ Unknown |
| 2026-06-17 09:31:13 shown | 1084ms | 4 NS 1 A 2 MX | 🔒 Secure |