Domain Overview
DNS: ✓ 2mo ago
Checker: ✓ 2mo ago
sternfenster.co.uk
Yes
✓ Yes
Outlook
No
No
⚠ Yes
No
No
Did you mean: [email protected]
Checked via [email protected]
· 2026-03-24 05:57:59 UTC · ↺ Refresh
MX Hostnames
- eu-esec-02.heimdalsecurity.com
- eu-esec-01.heimdalsecurity.com
- sternfenster-co-uk.mail.protection.outlook.com
MX Priorities
- eu-esec-01.heimdalsecurity.com: 0
- eu-esec-02.heimdalsecurity.com: 1
- sternfenster-co-uk.mail.protection.outlook.com: 5
A / AAAA Records
- 79.170.40.4
Mail Server IPs
- 20.50.183.146 ↩ eu-esec-01.heimdalsecurity.com
- 20.50.183.144 ↩ eu-esec-01.heimdalsecurity.com
- 52.101.99.0 ↩ mail-cwxp265cu00600.inbound.protection.outlook.com
- 52.101.89.2 ↩ mail-lo3p265cu00302.inbound.protection.outlook.com
- 52.101.89.0 ↩ mail-lo2p265cu02300.inbound.protection.outlook.com
- 52.101.99.2 ↩ mail-cwxp265cu00502.inbound.protection.outlook.com
- 2a01:111:f403:ca1a:: ↩ mail-cwxp265cu00500.inbound.protection.outlook.com
- 2a01:111:f403:ca0b::1 ↩ mail-lo3p265cu00301.inbound.protection.outlook.com
- 2a01:111:f403:ca0b::2 ↩ mail-lo0p265cu00202.inbound.protection.outlook.com
- 2a01:111:f403:ca1a::1 ↩ mail-cwxp265cu00601.inbound.protection.outlook.com
SOA Record
Raw SOA
ns.heartinternet.co.uk hostmaster.mainnameserver.com 2025081361 10800 600 2419200 3600
Primary NS (mname)
ns.heartinternet.co.uk
Admin Email (rname)
hostmaster@mainnameserver.com
Serial
2025081361
Refresh
10800s
Retry
600s
Expire
2419200s
Minimum TTL
3600s
Nameservers (NS)
ns2.heartinternet.co.uk
ns.heartinternet.co.uk
SPF Record
✓ Strict (-all)
v=spf1 a mx ip4:193.117.197.224/28 ip4:52.56.236.175 ip4:79.170.40.4 ip4:20.50.183.144/29 include:spf.protection.outlook.com include:spf-uk.emailsignatures365.com include:spf-esec.heimdalsecurity.com include:amazonses.com include:139521839.spf10.hubspotemail.net -all
📊 DNS lookups: 7/10
✓ Hard fail (-all) — strict enforcement
DMARC Record
✗ p=none
v=DMARC1; p=none
⚠ p=none — monitoring only, no enforcement
📋 SPF alignment: Relaxed
· DKIM alignment: Relaxed
⚠ No aggregate reports (rua= not set)
DKIM Selectors
✓ 3 found
selector1._domainkey
selector2._domainkey
k1._domainkey
✓ Public key: 392 chars (valid)
✓ DKIM properly configured for selector: selector1
Checked: google, selector1/2, default, mail, dkim, k1, s1/2, zoho, sendgrid, mxvault, amazonses
All TXT Records
2 records- SPFv=spf1 a mx ip4:193.117.197.224/28 ip4:52.56.236.175 ip4:79.170.40.4 ip4:20.50.183.144/29 include:spf.protection.outlook.com include:spf-uk.emailsignatures365.com include:spf-esec.heimdalsecurity.com include:amazonses.com include:139521839.spf10.hubspotemail.net -all
- knowbe4-site-verification=a2a119fd82d8c003b0dfe75ea0c8f324
Free · No signup required
Add email validation to your forms
Block disposable emails, validate MX records, detect role accounts — unlimited, forever free.
<script src="https://check.verifyswift.com/"></script>
One line of code · Works on any site
See demo & docs
Deep verification
Full email verification for sternfenster.co.uk
SMTP handshake, catch-all detection, custom validation rules, actual deliverability tests, and more.
No credit card required
Get 1,000 Free Credits