mail.c21.co.jp - robtex.com
mail.c21.co.jp
| DNSSEC | ⚠️ Not signed | ||||||
| A | 163.43.197.179🇯🇵 SAKURA-B163.43.0.0/16 (TOKYO) SAKURA Internet // EAST JAPAN BACKBONE Sakaisuji Honmachi Bldg. 9F 1-8-14 Minami-Honmachi, Chuo-ku Osaka 541-0054, Japan | ||||||
| PTR | www50139.sakura.ne.jp | ||||||
| NS | master.dns.ne.jp ⭐ | ||||||
| A | 210.224.172.18🇯🇵 SAKURA-C210.224.160.0/19 (1/OSAKA) SAKURA Internet // WEST JAPAN BACKBONE 1-8-15 Kyutaro-cho, Chuo Osaka 541-0056, Japan | ||||||
| PTR | master.dns.ne.jp | ||||||
| NS | ns1.dns.ne.jp ⚠️ Not in parent delegation | ||||||
| A | 61.211.236.1🇯🇵 SAKURA-B61.211.236.0/24 (4/TOKYO) SAKURA Internet // EAST JAPAN BACKBONE 1-8-15 Kyutaro-cho, Chuo Osaka 541-0056, Japan | ||||||
| PTR | ns1.dns.ne.jp | ||||||
| NS | ns2.dns.ne.jp ⚠️ Not in parent delegation | ||||||
| A | 133.167.21.1🇯🇵 SAKURA-C133.167.21.0/24 (OSAKA) SAKURA Internet // WEST JAPAN BACKBONE Grand Front Osaka Tower A 35F, 4-20 Ofukacho, Kita-ku, Osaka, Osaka 530-0011, Japan | ||||||
| PTR | ns2.dns.ne.jp | ||||||
| MX | mail.c21.co.jp ⭐ | ||||||
| A | 163.43.197.179🇯🇵 SAKURA-B163.43.0.0/16 (TOKYO) SAKURA Internet // EAST JAPAN BACKBONE Sakaisuji Honmachi Bldg. 9F 1-8-14 Minami-Honmachi, Chuo-ku Osaka 541-0054, Japan | ||||||
| PTR | www50139.sakura.ne.jp | ||||||
| SOA | master.dns.ne.jptech@sakura.ad.jp 2024-01-30 #11 | ||||||
c21.co.jp
| DNSSEC | ⚠️ Not signed | ||||||
| A | 153.125.228.7🇯🇵 SAKURA-B153.125.224.0/20 (TOKYO) SAKURA Internet // EAST JAPAN BACKBONE Sakaisuji Honmachi Bldg. 9F 1-8-14 Minami-Honmachi, Chuo-ku Osaka 541-0054, Japan | ||||||
| NS | master.dns.ne.jp ⭐ | ||||||
| NS | ns1.dns.ne.jp | ||||||
| NS | ns2.dns.ne.jp | ||||||
| MX | mail.c21.co.jp ⭐ | ||||||
| TXT | v=spf1 include:spf.macly.jp include:spfsakura.macly.jp include:spfblue.macly.... | ||||||
| SOA | master.dns.ne.jptech@sakura.ad.jp 2025-12-17 #4 | ||||||
WOT: SAFE (61/100)
MX for
Same first word
Similar names
DNS History
6 records (5 active, 1 former)
●MXmail.c21.co.jp2026-06-06 → 2026-07-19 · 2 obs
● 2026-07-19 09:13:48
○A1.33.171.612015-10-22 → 2016-08-10 · 4 obs
● 2016-08-10 12:54:26
○ 2026-06-06 19:41:28
○ 2026-07-19 09:13:48
●A163.43.197.1792026-06-06 → 2026-07-19 · 3 obs
● 2026-06-06 19:41:28
● 2026-07-19 09:13:48
🔍 DNS Trace
📋 Delegation Chain
| Zone | Nameservers | Glue |
|---|---|---|
| jp | e.dns.jp, g.dns.jp, c.dns.jp, a.dns.jp... | - |
| c21.co.jp | ns1.dns.ne.jp, ns2.dns.ne.jp | 2 records |
✅ Authoritative Response
Server:133.167.21.1
NS records: ns1.dns.ne.jp, ns2.dns.ne.jp
🔒 DNSSEC Status
⚠️ Insecure (no DNSSEC)
No DS record for c21.co.jp (unsigned zone)
⏱️ Timing
Total: 919ms | Queries: -
📄 Records
| Type | Count | Sample Data |
|---|---|---|
| A | 1 | 163.43.197.179 |
| NS | 2 | ns1.dns.ne.jp, ns2.dns.ne.jp |
| MX | 1 | mail.c21.co.jp (pri: 10) |
| SOA | 1 | master.dns.ne.jp tech.sakura.ad.jp |
📌 Glue Records Collected
Total: 2
Out-of-bailiwick: 2 (ns2.dns.ne.jp, ns1.dns.ne.jp)
Analysis
Mail Server Role
mail.c21.co.jp acts as an MX server for mail.c21.co.jp and c21.co.jp.
IP Addresses
mail.c21.co.jp directs to one IP number, which is 163.43.197.179.
Among the host names that share IP numbers with mail.c21.co.jp are www.zentoshin.com, www.yamadaseimitsu.co.jp, mail.forumcars.jp and two others.
Name Servers
mail.c21.co.jp is served by three name servers: master.dns.ne.jp, ns1.dns.ne.jp and ns2.dns.ne.jp.
At least some of mail.c21.co.jp's name servers are shared with other domains, for example ecluse.jp, welcart-org.sakura.ne.jp, asura.info and two more.
master.dns.ne.jp has IP address 210.224.172.18, ns1.dns.ne.jp has IP address 61.211.236.1 and ns2.dns.ne.jp has IP address 133.167.21.1 — one address each.
Mail Servers
The MX record for mail.c21.co.jp points to a single mail server: mail.c21.co.jp.
mail.c21.co.jp and domains like c21.co.jp share an identical mail server configuration.
mail.c21.co.jp resolves to 163.43.197.179 and no other IP number.