smtp2go.com

Checked 22 October 2026, 10:44 UTC · via 8.8.8.8
!Passed with warnings
22 passed 5 warnings 0 failed 4 info

Registration

info

.com generic · GoDaddy.com, LLC · expires 2028-06-20

Found

TLD
.com (generic)
ICANN policies apply
yes
Registrar
GoDaddy.com, LLC
Registered
20 June 2006
Last changed
11 June 2025
Expires
20 June 2028
Status
client delete prohibited, client renew prohibited, client transfer prohibited, client update prohibited
Registry nameservers
ns2.smtpcorp.com, sns1.treshna.co.nz, sns2.treshna.co.nz, sns3.treshna.co.nz
RDAP server
https://rdap.verisign.com/com/v1/

Checks

  • i
    .com is a generic TLD (gTLD)
    Generic TLD under an ICANN registry agreement: ICANN-accredited registrars, UDRP and RDAP apply.
    #1
  • ✓ TLD delegated and signed #2
    .com is delegated in the root zone and DNSSEC-signed.
  • ✓ Expires on 2028-06-20 #3
    The registration is valid until 2028-06-20 (606 days).
  • ✓ Transfer locked #4
    Registry status: client delete prohibited, client renew prohibited, client transfer prohibited, client update prohibited.
  • ✓ Registry and delegation match #5
    The nameservers registered at the registry are the ones published in DNS.

Delegation

warn

ns2.smtpcorp.com, sns1.treshna.co.nz, sns2.treshna.co.nz, sns3.treshna.co.nz

Found

Parent zone
com
Delegation from
a.gtld-servers.net (192.5.6.30)
NS at the parent
ns2.smtpcorp.com, sns1.treshna.co.nz, sns2.treshna.co.nz, sns3.treshna.co.nz
NS in the zone
ns2.smtpcorp.com, ns4.smtpcorp.com, sns3.treshna.co.nz, sns4.treshna.co.nz
NameserverAddressesNetwork (AS)Glue
ns2.smtpcorp.com185.3.94.65AS63949 AKAMAI-LINODE-AP - Akamai Connected Cloud, SG207.58.142.213
ns4.smtpcorp.com (zone only)45.79.143.133AS63949 AKAMAI-LINODE-AP - Akamai Connected Cloud, SG-
sns1.treshna.co.nz (parent only)198.74.56.28AS63949 AKAMAI-LINODE-AP - Akamai Connected Cloud, SG-
sns2.treshna.co.nz (parent only)185.3.94.65AS63949 AKAMAI-LINODE-AP - Akamai Connected Cloud, SG-
sns3.treshna.co.nz45.79.143.133AS63949 AKAMAI-LINODE-AP - Akamai Connected Cloud, SG-
sns4.treshna.co.nz (zone only)198.74.56.28AS63949 AKAMAI-LINODE-AP - Akamai Connected Cloud, SG-

Checks

  • ✓ 4 nameservers #6
    Delegated to ns2.smtpcorp.com, sns1.treshna.co.nz, sns2.treshna.co.nz, sns3.treshna.co.nz.
  • !
    NS sets differ
    The nameservers at the parent and in the zone should be the same. Only at the parent: sns1.treshna.co.nz, sns2.treshna.co.nz; only in the zone: ns4.smtpcorp.com, sns4.treshna.co.nz. ns2.smtpcorp.com, ns4.smtpcorp.com, sns1.treshna.co.nz, sns2.treshna.co.nz, sns3.treshna.co.nz, sns4.treshna.co.nz report NS ns2.smtpcorp.com ns4.smtpcorp.com sns3.treshna.co.nz sns4.treshna.co.nz.
    #7
  • !
    Glue differs from the zone
    The addresses at the parent (glue) differ from the addresses in the zone: ns2.smtpcorp.com (glue 207.58.142.213, zone 185.3.94.65). Update the glue at your registrar.
    #8
  • ✓ All names resolve #9
    Every nameserver name has an address and is not an alias.
  • ✓ Nameservers in different networks #10
    The nameservers are spread over 3 IPv4 /24s and 0 IPv6 /48s.
  • i
    All nameservers in one AS
    All nameserver addresses are announced by one network operator (AS63949 (AKAMAI-LINODE-AP - Akamai Connected Cloud, SG): 6 addresses). An outage or attack on that network affects all nameservers; large anycast providers mitigate this, but a secondary DNS provider adds independence.
    #11
  • ✓ Nameserver names under 2 TLDs #12
    Nameserver names use the TLDs .com, .nz.
  • !
    No IPv6
    None of the nameservers has an IPv6 address, so IPv6-only resolvers can't reach them.
    #13

Nameservers

warn

6 of 6 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
ns2.smtpcorp.com 185.3.94.65NOERROR, 15 ms, authoritativenoyes / yesrefused9.18.49-1~deb12u2-Debian
ns4.smtpcorp.com 45.79.143.133NOERROR, 90 ms, authoritativenoyes / yesrefused9.18.44-1~deb12u1-Debian
sns1.treshna.co.nz 198.74.56.28NOERROR, 91 ms, authoritativenoyes / yesrefused9.20.29-1~deb13u1-Debian
sns2.treshna.co.nz 185.3.94.65NOERROR, 16 ms, authoritativenoyes / yesrefused9.18.49-1~deb12u2-Debian
sns3.treshna.co.nz 45.79.143.133NOERROR, 92 ms, authoritativenoyes / yesrefused9.18.44-1~deb12u1-Debian
sns4.treshna.co.nz 198.74.56.28NOERROR, 91 ms, authoritativenoyes / yesrefused9.20.29-1~deb13u1-Debian

Checks

  • ✓ All respond #14
    All 6 nameserver addresses answered.
  • ✓ All authoritative #15
    Every responding nameserver answers authoritatively for the zone.
  • ✓ No recursion #16
    The nameservers do not answer recursive queries for other domains.
  • !
    Software version disclosed
    These nameservers report their software version via version.bind/version.server, which helps attackers find known vulnerabilities: ns2.smtpcorp.com: "9.18.49-1~deb12u2-Debian"; ns4.smtpcorp.com: "9.18.44-1~deb12u1-Debian"; sns1.treshna.co.nz: "9.20.29-1~deb13u1-Debian"; sns2.treshna.co.nz: "9.18.49-1~deb12u2-Debian"; sns3.treshna.co.nz: "9.18.44-1~deb12u1-Debian"; sns4.treshna.co.nz: "9.20.29-1~deb13u1-Debian". Hide or replace the version string.
    #17
  • ✓ Zone transfers refused #18
    No nameserver allows a zone transfer to the public.
  • ✓ TCP supported #19
    All nameservers answer over TCP.
  • ✓ EDNS supported #20
    All nameservers support EDNS(0).
  • ✓ Public addresses #21
    All nameserver addresses are publicly routable.

SOA

pass

serial 2026090784 · primary ns2.smtpcorp.com

Found

Primary (MNAME)
ns2.smtpcorp.com
Contact (RNAME)
hostmaster.smtp2go.com
Serial
2026090784
Refresh / retry
14400 s / 3600 s
Expire
1209600 s
Negative TTL
900 s

Serial per nameserver

NameserverSerial
ns2.smtpcorp.com (185.3.94.65)2026090784
ns4.smtpcorp.com (45.79.143.133)2026090784
sns1.treshna.co.nz (198.74.56.28)2026090784
sns2.treshna.co.nz (185.3.94.65)2026090784
sns3.treshna.co.nz (45.79.143.133)2026090784
sns4.treshna.co.nz (198.74.56.28)2026090784

Checks

  • ✓ Serial 2026090784 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 4h, retry 1h, expire 14d, negative TTL 15m.
  • ✓ Primary is a public nameserver #24
    The primary nameserver ns2.smtpcorp.com is one of the listed nameservers.
  • ✓ Contact hostmaster@smtp2go.com #25
    The SOA RNAME hostmaster.smtp2go.com means hostmaster@smtp2go.com.
  • ✓ Date-based serial #26
    The serial 2026090784 follows the YYYYMMDDnn convention (2026-09-07).

DNSSEC

warn

Not signed

Found

Validated by resolver
no

Checks

  • !
    Not signed
    The zone is not signed with DNSSEC, so answers can be spoofed. Enable DNSSEC at your DNS provider and publish the DS record at your registrar.
    #27

Records

info

14 records at the apex

Found

Read from
185.3.94.65:53
TypeValueTTL
SOAns2.smtpcorp.com. hostmaster.smtp2go.com. 2026090784 14400 3600 1209600 900600
NSns4.smtpcorp.com.600
NSsns4.treshna.co.nz.600
NSns2.smtpcorp.com.600
NSsns3.treshna.co.nz.600
A43.228.184.5600
MX10 alt4.aspmx.l.google.com.3600
MX1 aspmx.l.google.com.3600
MX5 alt2.aspmx.l.google.com.3600
MX5 alt1.aspmx.l.google.com.3600
MX10 alt3.aspmx.l.google.com.3600
TXT"google-site-verification=soeGlTttTYwUL2pNnJrZhPKlEkv_1ldMmCeoQe1ZkBA"14400
TXT"v=spf1 ip4:210.48.71.200 ip4:210.48.71.172 ip4:50.56.72.228 ip4:210.48.71.198/30 ip4:50.57.187.177 ip4:167.89.2.95 include:mail.zendesk.com include:spf.smtp2go.com include:_spf.google.com -all"14400
TXT"facebook-domain-verification=pdmbr1cb56arylrd3m54nn6vd3xub7"14400

Checks

  • ✓ TTLs within range #32
    TTLs: A 10m, MX 1h, NS 10m. The NS TTL at the parent is 2d and in the zone 10m; resolvers may use either.
  • ✓ No CNAME at the apex #33
    The zone apex has no CNAME record.
  • i
    Wildcard record
    A random name under the zone resolves, so there is a wildcard (*) record. Typos and non-existent hosts resolve too, which can confuse mail and certificate checks.
    #34
  • i
    No CAA records
    Without CAA records any certificate authority may issue certificates for this domain. A CAA record limits issuance to the CAs you use.
    #35