Domain Overview
DNS: ✓ 2mo ago
Checker: ✓ 2mo ago
cstsinc.com
Yes
✓ Yes
Outlook
No
No
⚠ Yes
No
No
Checked via [email protected]
· 2026-04-01 05:35:53 UTC · ↺ Refresh
MX Hostnames
- cstsinc-com.mail.protection.outlook.com
MX Priorities
- cstsinc-com.mail.protection.outlook.com: 0
A / AAAA Records
- 54.236.189.64 ↩ ec2-54-236-189-64.compute-1.amazonaws.com
Mail Server IPs
- 52.101.41.183 ↩ mail-byapr04cu00307.inbound.protection.outlook.com
- 52.101.8.34 ↩ mail-dm2pr04cu00102.inbound.protection.outlook.com
- 52.101.11.2 ↩ mail-sn1pr03cu00102.inbound.protection.outlook.com
- 52.101.41.22 ↩ mail-sj2pr05cu00406.inbound.protection.outlook.com
- 2a01:111:f403:c936:: ↩ mail-cy1pr05cu00400.inbound.protection.outlook.com
- 2a01:111:f403:f908::1 ↩ mail-bn1pr04cu00101.inbound.protection.outlook.com
- 2a01:111:f403:f90d::1 ↩ mail-sn1pr0501cu00301.inbound.protection.outlook.com
- 2a01:111:f403:f909:: ↩ mail-bn6pr04cu00200.inbound.protection.outlook.com
SOA Record
Raw SOA
dns051.a.register.com root.register.com 2017052424 28800 7200 604800 3600
Primary NS (mname)
dns051.a.register.com
Admin Email (rname)
root@register.com
Serial
2017052424
Refresh
28800s
Retry
7200s
Expire
604800s
Minimum TTL
3600s
Nameservers (NS)
dns051.a.register.com
dns151.b.register.com
dns176.d.register.com
dns249.c.register.com
SPF Record
✓ Strict (-all)
v=spf1 include:spf.protection.outlook.com -all
📊 DNS lookups: 1/10
✓ Hard fail (-all) — strict enforcement
DMARC Record
✗ MissingNo DMARC record — emails cannot be rejected on auth failure.
DKIM Selectors
✗ None detectedNo DKIM records found for common selectors — your provider may use a custom selector name.
Checked: google, selector1/2, default, mail, dkim, k1, s1/2, zoho, sendgrid, mxvault, amazonses
All TXT Records
2 records- 3r8g30jf4r455jleug42244qpv
- SPFv=spf1 include:spf.protection.outlook.com -all
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