customer.io

Valid Email Server
Live data — DNS records and disposable check were just fetched and saved.

Domain Overview

DNS: ⚡ live Checker: ⚡ live
customer.io
Yes
✓ Yes
Google
No
No
⚠ Yes
No
No

Checked via [email protected] · 2026-07-01 16:01:32 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

  • alt1.aspmx.l.google.com
  • aspmx2.googlemail.com
  • aspmx3.googlemail.com
  • alt2.aspmx.l.google.com
  • aspmx.l.google.com

MX Priorities

  • alt2.aspmx.l.google.com: 5
  • aspmx.l.google.com: 1
  • aspmx2.googlemail.com: 10
  • aspmx3.googlemail.com: 10
  • alt1.aspmx.l.google.com: 5

A / AAAA Records

  • 76.76.21.21 (no PTR)

Mail Server IPs

  • 172.253.116.27 ↩ dj-in-f27.1e100.net
  • 2a00:1450:400b:c02::1b ↩ dj-in-f27.1e100.net
  • 142.251.163.27 ↩ wv-in-f27.1e100.net
  • 2607:f8b0:4004:c1d::1a ↩ ww-in-f26.1e100.net
  • 108.177.123.26 ↩ lcscld-in-f26.1e100.net
  • 2800:3f0:4003:c0f::1a (no PTR)
  • 2800:3f0:4003:c0f::1b (no PTR)

SOA Record

Raw SOA ns-1181.awsdns-19.org awsdns-hostmaster.amazon.com 1 7200 900 1209600 86400
Primary NS (mname)
ns-1181.awsdns-19.org
Admin Email (rname)
awsdns-hostmaster@amazon.com
Serial
1
Refresh
7200s
Retry
900s
Expire
1209600s
Minimum TTL
86400s

Nameservers (NS)

ns-1181.awsdns-19.org
ns-1893.awsdns-44.co.uk
ns-499.awsdns-62.com
ns-618.awsdns-13.net

SPF Record

✓ Soft Fail (~all)
v=spf1 include:helpscoutemail.com include:_spf.google.com include:servers.mcsv.net include:amazonses.com include:mail.zendesk.com ~all
📊 DNS lookups: 5/10
~ Soft fail (~all) — moderate enforcement

DMARC Record

~ Quarantine
v=DMARC1; p=quarantine; sp=quarantine; rua=mailto:[email protected],mailto:[email protected]; aspf=r; pct=100
~ Quarantine — good protection (failing mail goes to spam)
📋 SPF alignment: Relaxed · DKIM alignment: Relaxed
📧 Reports → mailto:[email protected],mailto:[email protected]
↳ Subdomain policy: quarantine

DKIM Selectors

✓ 1 found
google._domainkey
✓ Public key: 216 chars (valid)
✓ DKIM properly configured for selector: google

Checked: google, selector1/2, default, mail, dkim, k1, s1/2, zoho, sendgrid, mxvault, amazonses

All TXT Records

25 records
  • google-site-verification=HbwteWh_QF6HnNCDLL_1X_GRwURBkYEdFAVM00rxf_k
  • slack-domain-verification=XRnWU545ZVlzHN85aeTWX7xzunEJk8Ouav9KjN7Q
  • airtable-verification=a839ac25097d07e90b6725421494b506
  • SPFv=spf1 include:helpscoutemail.com include:_spf.google.com include:servers.mcsv.net include:amazonses.com include:mail.zendesk.com ~all
  • sinch-domain-verification=77675a95-7309-44bf-9483-5f9020edc778
  • asv=8738dd37f3c5a1368cba93d24b4a1e17
  • 1password-site-verification=NKRDO4YCMBDD7KNUO4PN6RZCA4
  • OSSRH-70026
  • zapier-domain-verification-challenge=3373ff99-18e1-4a49-8e81-67d830eb392b
  • mixpanel-domain-verify=d5c389d5-df00-473a-8263-3932c19beecb
  • docusign=48e7526a-7539-4ad0-b672-7a94c3a20c29
  • cursor-domain-verification-m2k2b5=XfoK2FPHAUqoNHiCpHtqY2fXP
  • anthropic-domain-verification-h4s30h=RXWAAyC4VDThCnWjaprWPkUET
  • notion-domain-verification=DHmczCmyAqc8TGp6DPbfWBxLb9lSgvPv7wSOiiJfAJK
  • loom-site-verification=4dac5f34468e49a299444383229599d5
  • google-site-verification=gsxlVNPtm1JCawWVNMCOVuWLK9lhzdr4Dofz-V-lovo
  • facebook-domain-verification=62g2j16g5qkvf38ekdrtxiez0bsqei
  • have-i-been-pwned-verification=a9d6f2edb8654dcfe04e310cdc9a000a
  • MS=ms56053829
  • ps-cd-verification=6d210b55-ec4b-4105-a1d7-7a73c78619fd
  • openai-domain-verification=dv-icOHzM0IplqgpTNoO3nJaRCX
  • linear-domain-verification=wetdfvhymmbh
  • hubspot-developer-verification=NDkzOTIwZWMtMDVkNS00YTAzLThlMDQtZDJmYzVjNzc5Zjgw
  • jetbrains-domain-verification=rdxczp2suguw502vrx4cqksy
  • miro-verification=89a8ecb5df4f4febc758723fcfabd5af59041414
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 customer.io

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

No credit card required
Get 1,000 Free Credits