Domain Overview
DNS: ✓ just now
Checker: ✓ just now
is-sandbox.com
Yes
✓ Yes
Unknown
No
No
⚠ Yes
No
No
Checked via [email protected]
· 2026-07-19 08:06:13 UTC · ↺ Refresh
MX Hostnames
- mail.is-sandbox.com
MX Priorities
- mail.is-sandbox.com: 10
A / AAAA Records
- 4.79.161.106 (no PTR)
Mail Server IPs
- 4.79.161.102 (no PTR)
SOA Record
Raw SOA
ns20.digicertdns.com dns.digicertdns.com 2009010111 43200 3600 1209600 180
Primary NS (mname)
ns20.digicertdns.com
Admin Email (rname)
dns@digicertdns.com
Serial
2009010111
Refresh
43200s
Retry
3600s
Expire
1209600s
Minimum TTL
180s
Nameservers (NS)
ns24.digicertdns.net
ns23.digicertdns.net
ns21.digicertdns.com
ns20.digicertdns.com
ns22.digicertdns.com
ns25.digicertdns.net
SPF Record
✓ Strict (-all)
v=spf1 a mx a:mail.is-sandbox.com ip4:4.79.161.102 -all
📊 DNS lookups: 3/10
✓ Hard fail (-all) — strict enforcement
DMARC Record
~ Quarantine
v=DMARC1; p=quarantine;
~ Quarantine — good protection (failing mail goes to spam)
📋 SPF alignment: Relaxed
· DKIM alignment: Relaxed
⚠ No aggregate reports (rua= not set)
DKIM Selectors
✓ 1 found
default._domainkey
✓ Public key: 216 chars (valid)
✓ DKIM properly configured for selector: default
Checked: google, selector1/2, default, mail, dkim, k1, s1/2, zoho, sendgrid, mxvault, amazonses
All TXT Records
3 records- gridinsoft-verify=3g9kjffhh6vr1hse0bf2y8f4xr70karts9uymkog0a9bih12xsxwzo22i227ftri
- 783qenlv6om6m3gtl1d8f3v17i
- SPFv=spf1 a mx a:mail.is-sandbox.com ip4:4.79.161.102 -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 is-sandbox.com
SMTP handshake, catch-all detection, custom validation rules, actual deliverability tests, and more.
No credit card required
Get 1,000 Free Credits