letterhead.cz - robtex.com
letterhead.cz
| DNSSEC | ⚠️ Not signed | ||||||
| A | 81.91.85.229🇨🇿 WEB4U81.91.80.0/21 | ||||||
| PTR | m136-web2.server4u.cz | ||||||
| NS | ns1.cyberhost.cz ⭐ ⚠️ Not in parent delegation | ||||||
| A | 81.91.85.93🇨🇿 WEB4U81.91.80.0/21 | ||||||
| PTR | mail.cybers.cz | ||||||
| NS | ns1.aria-studio.cz ⚠️ Not in zone NS records | ||||||
| A | 81.91.85.93🇨🇿 WEB4U81.91.80.0/21 | ||||||
| PTR | mail.cybers.cz | ||||||
| NS | ns2.aria-studio.cz ⚠️ Not in zone NS records | ||||||
| A | 81.91.85.252🇨🇿 WEB4U81.91.80.0/21 | ||||||
| PTR | ns2.cybers.cz | ||||||
| NS | ns2.cyberhost.cz ⚠️ Not in parent delegation | ||||||
| A | 81.91.85.252🇨🇿 WEB4U81.91.80.0/21 | ||||||
| PTR | ns2.cybers.cz | ||||||
| MX | mail.letterhead.cz ⭐ | ||||||
| A | 81.91.85.93🇨🇿 WEB4U81.91.80.0/21 | ||||||
| PTR | mail.cybers.cz | ||||||
| SOA | ns1.cyberhost.czadmin@web4u.cz serial=2608060018 | ||||||
cz
| DNSSEC | 🔒 Signed (DS record present) | ||||||
| NS | a.ns.nic.cz ⭐ | ||||||
| NS | b.ns.nic.cz | ||||||
| NS | c.ns.nic.cz | ||||||
| NS | d.ns.nic.cz | ||||||
| SOA | a.ns.nic.czhostmaster@nic.cz serial=1785966440 | ||||||
Subdomains
mail.letterhead.cz |
Same first word
letterhead.email |
letterhead.co.uk |
letterhead.in |
letterhead.fi |
letterhead.com.au |
letterhead.cz |
letterhead.it |
letterhead.com |
Similar names
theatreled.com |
etherdelta.com |
deltaether.com |
leatherted.com |
etherdelta.io |
deltathree.cn |
deltathree.com |
threedelta.com |
redathlete.com |
DNS History
15 records (6 active, 9 former)
○NSns.wedos.com2015-08-05 → 2016-03-03 · 4 obs
● 2016-03-03 08:22:56
○ 2016-06-22 04:47:40
○ 2026-08-05 22:22:44
○NSns.wedos.cz2015-08-05 → 2016-03-03 · 4 obs
● 2016-03-03 08:22:56
○ 2016-06-22 04:47:40
○ 2026-08-05 22:22:44
○NSns.wedos.eu2015-08-05 → 2016-03-03 · 4 obs
● 2016-03-03 08:22:56
○ 2016-06-22 04:47:40
○ 2026-08-05 22:22:44
○NSns.wedos.net2015-08-05 → 2016-03-03 · 4 obs
● 2016-03-03 08:22:56
○ 2016-06-22 04:47:40
○ 2026-08-05 22:22:44
●NSns1.aria-studio.cz2026-07-01 → 2026-08-05 · 3 obs
● 2026-07-01 00:31:32
● 2026-08-05 22:22:44
●NSns1.cyberhost.cz2016-06-22 → 2026-08-05 · 3 obs
● 2016-06-22 04:47:40
● 2026-08-05 22:22:44
●NSns2.aria-studio.cz2026-07-01 → 2026-08-05 · 3 obs
● 2026-07-01 00:31:32
● 2026-08-05 22:22:44
●NSns2.cyberhost.cz2016-06-22 → 2026-08-05 · 3 obs
● 2016-06-22 04:47:40
● 2026-08-05 22:22:44
●MXmail.letterhead.cz2016-06-22 → 2026-08-05 · 3 obs
● 2016-06-22 04:47:40
● 2026-08-05 22:22:44
○MXmx10.prisedni.cz2015-08-05 → 2016-03-03 · 4 obs
● 2016-03-03 08:22:56
○ 2016-06-22 04:47:40
○ 2026-08-05 22:22:44
○MXmx20.prisedni.cz2015-08-05 → 2016-03-03 · 4 obs
● 2016-03-03 08:22:56
○ 2016-06-22 04:47:40
○ 2026-08-05 22:22:44
○A217.117.216.1582015-08-05 → 2015-08-05 · 3 obs
○ 2015-11-24 20:22:20
○ 2026-08-05 22:22:44
○A81.91.85.1352016-06-22 → 2017-05-15 · 5 obs
● 2016-06-22 04:47:40
● 2017-05-15 03:13:46
○ 2026-07-01 00:31:32
○ 2026-08-05 22:22:44
●A81.91.85.2292026-07-01 → 2026-08-05 · 3 obs
● 2026-07-01 00:31:32
● 2026-08-05 22:22:44
○A89.185.242.1112015-11-24 → 2016-03-03 · 5 obs
● 2015-11-24 20:22:20
● 2016-03-03 08:22:56
○ 2016-06-22 04:47:40
○ 2026-08-05 22:22:44
🔍 DNS Trace
📋 Delegation Chain
| Zone | Nameservers | Glue |
|---|---|---|
| cz | b.ns.nic.cz, c.ns.nic.cz, d.ns.nic.cz, a.ns.nic.cz | - |
| letterhead.cz | ns1.aria-studio.cz, ns2.aria-studio.cz | - |
✅ Authoritative Response
Server:81.91.85.252
NS records: ns1.aria-studio.cz, ns2.aria-studio.cz
🔒 DNSSEC Status
⚠️ Insecure (no DNSSEC)
No DS record for letterhead.cz (unsigned zone)
⏱️ Timing
Total: 1720ms | Queries: -
📄 Records
| Type | Count | Sample Data |
|---|---|---|
| A | 1 | 81.91.85.229 |
| NS | 2 | ns2.cyberhost.cz, ns1.cyberhost.cz |
| MX | 1 | mail.letterhead.cz (pri: 10) |
| SOA | 1 | ns1.cyberhost.cz admin.web4u.cz |
Analysis
Hierarchy
mail.letterhead.cz is a subdomain of letterhead.cz.
IP Addresses
letterhead.cz resolves to one IP address: 81.91.85.229.
autocermak.cz, ajakkladno.cz, redplus.cz and two other host names share IP numbers with letterhead.cz.
Name Servers
The authoritative name servers for letterhead.cz are ns1.aria-studio.cz, ns2.aria-studio.cz, ns1.cyberhost.cz and ns2.cyberhost.cz.
The name servers of letterhead.cz overlap at least partially with those of other domains — among them a-byte.eu, vanatka.cz, czechgamers.net and two more.
These name servers commonly appear in combination with the name servers ns3.cyberhost.cz.
Each of the host names ns1.aria-studio.cz, ns2.aria-studio.cz, ns1.cyberhost.cz and ns2.cyberhost.cz has one IP address: ns1.aria-studio.cz resolves to 81.91.85.93, ns2.aria-studio.cz resolves to 81.91.85.252, ns1.cyberhost.cz resolves to 81.91.85.93 and ns2.cyberhost.cz resolves to 81.91.85.252.
ns1.aria-studio.cz and ns1.cyberhost.cz each have 81.91.85.93 IP addresses.
ns2.aria-studio.cz and ns2.cyberhost.cz each have 81.91.85.252 IP addresses.
Mail Servers
Mail for letterhead.cz is handled by a single mail server, mail.letterhead.cz.
mail.letterhead.cz resolves to 81.91.85.93 and no other IP number.