protonmail.com

Checked 22 October 2026, 10:22 UTC · via 8.8.8.8
!Passed with warnings
31 passed 1 warning 0 failed 3 info

Registration

info

.com generic · MarkMonitor Inc. · expires 2028-08-21

Found

TLD
.com (generic)
ICANN policies apply
yes
Registrar
MarkMonitor Inc.
Registered
21 August 2010
Last changed
20 July 2026
Expires
21 August 2028
Status
client delete prohibited, client transfer prohibited, client update prohibited, server delete prohibited, server transfer prohibited, server update prohibited
Registry nameservers
ns1.protonmail.com, ns2.protonmail.com, ns3.protonmail.com
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 2028-08-21 #3
    The registration is valid until 2028-08-21 (668 days).
  • ✓ Transfer locked #4
    Registry status: client delete prohibited, client transfer prohibited, client update prohibited, server delete prohibited, server transfer prohibited, server update prohibited.
  • ✓ Registry and delegation match #5
    The nameservers registered at the registry are the ones published in DNS.

Delegation

warn

ns1.protonmail.com, ns2.protonmail.com, ns3.protonmail.com

Found

Parent zone
com
Delegation from
a.gtld-servers.net (192.5.6.30)
NS at the parent
ns1.protonmail.com, ns2.protonmail.com, ns3.protonmail.com
NS in the zone
ns1.protonmail.com, ns2.protonmail.com, ns3.protonmail.com
NameserverAddressesNetwork (AS)Glue
ns1.protonmail.com185.70.42.150AS62371 PROTON - Proton AG, CH185.70.42.150
ns2.protonmail.com176.119.200.150AS62371 PROTON - Proton AG, CH176.119.200.150
ns3.protonmail.com205.132.47.1AS42 WOODYNET-1 - WoodyNet, Inc., US205.132.47.1

Checks

  • ✓ 3 nameservers #6
    Delegated to ns1.protonmail.com, ns2.protonmail.com, ns3.protonmail.com.
  • ✓ Parent and zone agree #7
    The parent delegation and the zone's NS records list the same nameservers.
  • ✓ Glue present and correct #8
    Glue is published for the nameservers inside the zone: ns1.protonmail.com, ns2.protonmail.com, ns3.protonmail.com.
  • ✓ 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.
  • ✓ 2 autonomous systems #11
    The nameservers are spread over: AS42 (WOODYNET-1 - WoodyNet, Inc., US): 1 address; AS62371 (PROTON - Proton AG, CH): 2 addresses.
  • i
    All nameserver names under .com
    All nameserver names are under one TLD, so a problem with that TLD also makes the nameservers unreachable. Some operators use names under two TLDs for extra resilience.
    #12
  • !
    No IPv6
    None of the nameservers has an IPv6 address, so IPv6-only resolvers can't reach them.
    #13

Nameservers

info

3 of 3 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
ns1.protonmail.com 185.70.42.150NOERROR, 11 ms, authoritativenoyes / yesrefused-
ns2.protonmail.com 176.119.200.150NOERROR, 10 ms, authoritativenoyes / yesrefused-
ns3.protonmail.com 205.132.47.1NOERROR, 32 ms, authoritativenoyes / yesrefusedhost-pm

Checks

  • ✓ All respond #14
    All 3 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.
  • i
    Identifying string disclosed
    These nameservers answer version queries with a string that is not a version number: ns3.protonmail.com: "host-pm".
    #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 2502172703 · primary ns1.protonmail.com

Found

Primary (MNAME)
ns1.protonmail.com
Contact (RNAME)
support.protonmail.ch
Serial
2502172703
Refresh / retry
1200 s / 144 s
Expire
1814400 s
Negative TTL
7200 s

Serial per nameserver

NameserverSerial
ns1.protonmail.com (185.70.42.150)2502172703
ns2.protonmail.com (176.119.200.150)2502172703
ns3.protonmail.com (205.132.47.1)2502172703

Checks

  • ✓ Serial 2502172703 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 20m, retry 2m24s, expire 21d, negative TTL 2h.
  • ✓ Primary is a public nameserver #24
    The primary nameserver ns1.protonmail.com is one of the listed nameservers.
  • ✓ Contact support@protonmail.ch #25
    The SOA RNAME support.protonmail.ch means support@protonmail.ch.
  • ✓ Timestamp serial #26
    The serial 2502172703 is a Unix timestamp (2049-04-16 07:58 UTC).

DNSSEC

pass

Signed, DS published at parent

Found

Validated by resolver
yes
Denial of existence
NSEC3
NSEC3
0 iterations, 0-byte salt
Signatures valid until
5 November 2026

DS at the parent

Key tagAlgorithmDigestMatches a key
44693ECDSAP256SHA256 (13)SHA256 9F8A2A3CEEE67B74…yes

DNSKEY in the zone

Key tagRoleAlgorithm
44693KSK (257)ECDSAP256SHA256 (13)
56075ZSK (256)ECDSAP256SHA256 (13)

Checks

  • ✓ Signed and validated #27
    The zone is signed, the parent publishes a DS record, and the resolver validates the answers.
  • ✓ DS matches a key #28
    The DS record at the parent matches a key in the zone: key tag 44693 (SHA256).
  • ✓ Modern algorithms #29
    Key algorithms: ECDSAP256SHA256 (13).
  • ✓ Signatures valid until 2026-11-05 #30
    The earliest DNSKEY/SOA signature expires at 2026-11-05 11:14 UTC.
  • ✓ NSEC3 as recommended #31
    The zone uses NSEC3 with 0 iterations and no salt (RFC 9276).

Records

pass

19 records at the apex

Found

Read from
185.70.42.150:53
TypeValueTTL
SOAns1.protonmail.com. support.protonmail.ch. 2502172703 1200 144 1814400 72001200
NSns1.protonmail.com.1200
NSns2.protonmail.com.1200
NSns3.protonmail.com.1200
A185.70.42.121200
MX10 mailsec.protonmail.ch.1200
MX5 mail.protonmail.ch.1200
TXT"ahrefs-site-verification_4bdac6bbaa81e0d591d7c0f3ef238905c0521b69bf3d74e64d3775bcb2743afd"1200
TXT"brave-ledger-verification=66a7f27fb99949cc0c564ab98efcc58ea1bac3e97eb557c782ab2d44b49aefd7"1200
TXT"google-site-verification=uXVNQLivTppnZssXHtMY7QVn70Mpd0x2U8pKj324Krk"1200
TXT"google-site-verification=RVUCKIFDkg-Spau8kEohQRsgyHEBUQcVehZqF6PAQcQ"1200
TXT"v=spf1 include:_spf.protonmail.ch ~all"1200
TXT"google-site-verification=aq9zJnp3H3bNE0Y4D4rH5I5Dhj8VMaLYx0uQ7Rozfgg"1200
TXT"yandex-verification: 6059b187e78de544"1200
TXT"mailru-verification: 14505c6eb222c847"1200
CAA0 iodef "mailto:security@proton.me"1200
CAA0 issue "sectigo.com"1200
CAA0 issue "letsencrypt.org"1200
CAA0 issue "digicert.com"1200

Checks

  • ✓ TTLs within range #32
    TTLs: A 20m, MX 20m, NS 20m. The NS TTL at the parent is 2d and in the zone 20m; resolvers may use either.
  • ✓ No CNAME at the apex #33
    The zone apex has no CNAME record.
  • ✓ No wildcard #34
    Names that don't exist return NXDOMAIN.
  • ✓ CAA restricts issuance #35
    Certificates may be issued by: sectigo.com, letsencrypt.org, digicert.com.