xiii.nu

Valid Email Server
Domain Lookup › xiii.nu

Domain Overview

DNS: ✓ 8d ago Checker: ✓ 8d ago
xiii.nu
Yes
✓ Yes
Unknown
No
No
⚠ Yes
No
No
Did you mean: [email protected]

Checked via [email protected] · 2026-05-25 05:52:50 UTC · ↺ Refresh

Add email validation to your forms — free

Add our free script to block 10,000+ disposable domains + perform other checks. No signup, unlimited checks.

MX validation Disposable detection Role accounts
Add to your signup form
<script src="https://check.verifyswift.com/"></script>
One line · No registration · See full docs & demo → · Customize →

MX Hostnames

  • mail.protonmail.ch
  • mailsec.protonmail.ch

MX Priorities

  • mail.protonmail.ch: 10
  • mailsec.protonmail.ch: 20

A / AAAA Records

  • 23.44.201.5 ↩ a23-44-201-5.deploy.static.akamaitechnologies.com
  • 23.44.201.26 ↩ a23-44-201-26.deploy.static.akamaitechnologies.com

Mail Server IPs

  • 185.205.70.128 ↩ mail.protonmail.ch
  • 176.119.200.128 ↩ mail.protonmail.ch
  • 185.70.42.128 ↩ mail.protonmail.ch
  • 185.70.42.129 ↩ mailsec.protonmail.ch
  • 176.119.200.129 ↩ mailsec.protonmail.ch
  • 185.205.70.129 ↩ mailsec.protonmail.ch

SOA Record

Raw SOA a9-66.akam.net hostmaster.akamai.com 2019061351 43200 7200 604800 7200
Primary NS (mname)
a9-66.akam.net
Admin Email (rname)
hostmaster@akamai.com
Serial
2019061351
Refresh
43200s
Retry
7200s
Expire
604800s
Minimum TTL
7200s

Nameservers (NS)

a7-65.akam.net
a9-66.akam.net
a18-66.akam.net
a26-67.akam.net
a1-245.akam.net
a28-64.akam.net

SPF Record

✓ Soft Fail (~all)
v=spf1 include:_spf.protonmail.ch mx ~all
📊 DNS lookups: 2/10
~ Soft fail (~all) — moderate enforcement

DMARC Record

✗ p=none
v=DMARC1; p=none; rua=mailto:[email protected]
⚠ p=none — monitoring only, no enforcement
📋 SPF alignment: Relaxed · DKIM alignment: Relaxed
📧 Reports → mailto:[email protected]

DKIM Selectors

✗ None detected

No 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
  • protonmail-verification=bbb5e40afe694241d831de22672031997d87e82d
  • SPFv=spf1 include:_spf.protonmail.ch mx ~all
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 · Customize →
See demo & docs
Deep verification
Full email verification for xiii.nu

SMTP handshake, catch-all detection, custom validation rules, actual deliverability tests, and more.

No credit card required
Get 1,000 Free Credits