Domain Overview
DNS: ✓ 2mo ago
Checker: ✓ 2mo ago
robertkostin.com
Yes
✓ Yes
Outlook
No
No
⚠ Yes
No
No
Checked via [email protected]
· 2026-03-17 20:46:44 UTC · ↺ Refresh
MX Hostnames
- robertkostin-com.mail.protection.outlook.com
MX Priorities
- robertkostin-com.mail.protection.outlook.com: 0
A / AAAA Records
- 172.67.189.246 (no PTR)
- 104.21.89.164 (no PTR)
- 2606:4700:3030::ac43:bdf6
- 2606:4700:3031::6815:59a4
Mail Server IPs
- 52.101.10.16 ↩ mail-bn6pr21cu00500.inbound.protection.outlook.com
- 52.101.10.5 ↩ mail-bn6pr04cu00105.inbound.protection.outlook.com
- 52.101.41.4 ↩ mail-sj2pr05cu00204.inbound.protection.outlook.com
- 52.101.9.11 ↩ mail-bl2pr04cu00103.inbound.protection.outlook.com
- 2a01:111:f403:f90f::1 ↩ mail-sa9pr04cu00201.inbound.protection.outlook.com
- 2a01:111:f403:f90f:: ↩ mail-sa9pr04cu00100.inbound.protection.outlook.com
- 2a01:111:f403:c946::3 ↩ mail-ch0pr04cu00603.inbound.protection.outlook.com
- 2a01:111:f403:c803:: ↩ mail-bn1pr21cu00200.inbound.protection.outlook.com
SOA Record
Raw SOA
gerald.ns.cloudflare.com dns.cloudflare.com 2399251425 10000 2400 604800 1800
Primary NS (mname)
gerald.ns.cloudflare.com
Admin Email (rname)
dns@cloudflare.com
Serial
2399251425
Refresh
10000s
Retry
2400s
Expire
604800s
Minimum TTL
1800s
Nameservers (NS)
gerald.ns.cloudflare.com
violet.ns.cloudflare.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
✓ 2 found
s1._domainkey
s2._domainkey
✓ Public key: 392 chars (valid)
✓ DKIM properly configured for selector: s1
Checked: google, selector1/2, default, mail, dkim, k1, s1/2, zoho, sendgrid, mxvault, amazonses
All TXT Records
2 records- MS=ms69879384
- SPFv=spf1 include:spf.protection.outlook.com -all
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