Dataweaz

sk.ru

Summary

Registrar
RU-CENTER-RU
Status
REGISTERED
Created on
March 31, 2000
Expires on
April 30, 2027
Name servers
ns4-l2.nic.ru, ns8-l2.nic.ru, ns4-cloud.nic.ru, ns8-cloud.nic.ru, ns3-l2.nic.ru
Mail servers
mx7.sk.ru, mx8.sk.ru
DMARC
Quarantine
SPF
Soft
DKIM
1 key found
Website
See the website

Spoofing protection (DMARC)

Quarantine

E-mails spoofing this domain are sent to spam.

DMARC tells mail servers what to do with an e-mail that claims to come from sk.ru but fails SPF and DKIM checks.

Policy
Quarantine
Subdomain policy
Quarantine
Messages covered
100%
DKIM alignment
Relaxed
SPF alignment
Relaxed
Aggregate reports
[email protected]
Failure reports
[email protected]

Record

v=DMARC1; p=quarantine; sp=quarantine; rua=mailto:[email protected]; ruf=mailto:[email protected]; fo=1

Authorized senders (SPF)

Soft

E-mails sent by any other server are accepted but flagged as suspicious.

SPF lists the servers allowed to send e-mails for sk.ru.

RuleValueResult
mx—Allowed
ip495.213.155.52Allowed
ip491.224.82.158Allowed
ip45.252.65.112Allowed
ip477.108.80.184Allowed
ip45.252.64.96Allowed
ip45.252.64.121Allowed
ip495.213.210.180Allowed
ip45.252.65.37Allowed
ip45.252.65.38Allowed
ip45.252.64.197Allowed
ip45.252.65.116Allowed
includespf.unisender.comAllowed
all—Suspicious

Top-level DNS lookups: 2 of 10 allowed

Record

v=spf1 mx ip4:95.213.155.52 ip4:91.224.82.158 ip4:5.252.65.112 ip4:77.108.80.184 ip4:5.252.64.96 ip4:5.252.64.121 ip4:95.213.210.180 ip4:5.252.65.37 ip4:5.252.65.38 ip4:5.252.64.197 ip4:5.252.65.116 include:spf.unisender.com ~all

E-mail signing (DKIM)

DKIM keys published by sk.ru under the most common selectors. Other keys may exist under selectors specific to each sending service.

SelectorLikely serviceKeyStatus
smtp—RSA 2048 bitsActive

MX, SPF, DKIM and DMARC: the e-mail records

Four DNS records make a domain's e-mail work. MX says where e-mails sent to sk.ru arrive; SPF, DKIM and DMARC let mail servers check that an e-mail claiming to come from sk.ru was really sent by this domain, which protects it against spoofing.

MX

An MX (Mail Exchanger) record designates a server that receives e-mails sent to the domain. When someone writes to an @sk.ru address, their mail server queries the DNS for the domain's MX records, then delivers the message to the server they point to.

Example record

sk.ru  MX  10 mx1.sk.ru.
sk.ru  MX  20 mx2.sk.ru.

What the record contains

10, 20
Priority: the server with the lowest number is tried first. Servers with equal priority share the load.
mx1.sk.ru.
Host name of the mail server. It must point to an A or AAAA record: an IP address or an alias (CNAME) is not allowed here.
0 .
An MX "0 .", called a null MX, declares that the domain accepts no e-mail: sending servers give up at once instead of retrying.

Declaring at least two servers with different priorities avoids losing e-mails during an outage: sending servers retry for several days and fall back on the backup server. Without any MX, they try to deliver directly to the IP address of the domain.

SPF

SPF (Sender Policy Framework) is a TXT record listing the servers allowed to send e-mails on behalf of the domain. The receiving server checks that the sender is on this list. The final "all" rule says what to do with other servers: reject them (-all), flag their e-mails as suspicious (~all) or make no decision (?all).

Example record

sk.ru  TXT  "v=spf1 mx include:_spf.google.com ip4:192.0.2.10 -all"

What the record contains

v=spf1
Identifies the record as an SPF policy. It must come first.
ip4, ip6
Allows a specific IP address or an address range, for example ip4:192.0.2.0/24.
a, mx
Allows the addresses of the domain itself (A record) or those of its mail servers (MX).
include
Allows the servers of another domain, usually a sending service: include:_spf.google.com for Google Workspace.
-all, ~all
Final rule, applied to every other server. Its qualifier decides what happens to them: - rejects them, ~ flags their e-mails as suspicious, ? makes no decision, + accepts them (avoid it).

A domain must publish only one SPF record, and its evaluation cannot exceed 10 DNS lookups (include, a, mx, exists, redirect). Beyond that, mail servers treat it as invalid.

DKIM

DKIM (DomainKeys Identified Mail) signs every outgoing e-mail with a private key. The matching public key is published in a TXT record at selector._domainkey.sk.ru, so the recipient can check that the message really comes from the domain and was not altered on the way. The selector is chosen by each sending service and cannot be guessed: Dataweaz checks the most common ones (Google Workspace, Microsoft 365, Mailchimp, SendGrid…), so a key published under another selector may exist without appearing here.

Example record

google._domainkey.sk.ru  TXT  "v=DKIM1; k=rsa; p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA…"

What the record contains

v=DKIM1
Protocol version. Optional but recommended, in which case it must come first.
k
Key algorithm: rsa, the most common, or ed25519.
p
Public key, base64-encoded. An empty value means the key has been revoked.
t
Flags: y marks a key in testing, whose failures must not be penalized; s forbids its use for subdomains.

Each sending service publishes its key under its own selector (google, selector1, k1…), which allows several keys and seamless rotation. A 2048-bit RSA key is recommended today.

DMARC

DMARC (Domain-based Message Authentication, Reporting and Conformance) builds on SPF and DKIM. Published on _dmarc.sk.ru, it tells mail servers what to do with an e-mail that fails these checks (let it through, send it to spam or reject it) and where to send reports.

Example record

_dmarc.sk.ru  TXT  "v=DMARC1; p=quarantine; rua=mailto:[email protected]; adkim=r; aspf=r"

What the record contains

v=DMARC1
Identifies the record as a DMARC policy. It must come first.
p
Policy applied to e-mails that fail the checks: none (monitoring only), quarantine (spam folder) or reject.
sp
Subdomain policy. Without it, subdomains follow the domain's policy.
rua
Address that receives daily aggregate reports about e-mails sent on behalf of the domain, whether they pass the checks or not.
ruf
Address that receives detailed failure reports, message by message. Few providers still send them.
pct
Percentage of e-mails subject to the policy, for a gradual rollout. 100 by default.
adkim, aspf
DKIM and SPF alignment: r (relaxed, a subdomain of the same domain is enough) or s (strict, the domain must be identical).

To roll out DMARC without blocking legitimate e-mails, start with p=none and an rua address, analyze the reports to find every service sending on behalf of the domain, then move to quarantine and finally to reject.

DNS records of sk.ru

IP addresses (A and AAAA)

An A record maps the domain name to an IPv4 address: the address of the server that browsers contact to display the website. The AAAA record does the same for an IPv6 address. A domain can have several of them to spread visits across several servers.

TypeIP address
A91.221.164.121

Name servers (NS)

NS records designate the authoritative DNS servers of the domain: they answer every question about its other records (A, MX, TXT…). They are provided by the registrar, the hosting provider or a dedicated DNS service, and several servers are declared so that the domain keeps working if one of them fails.

ServerIP address
ns4-l2.nic.ru91.217.20.20
ns8-l2.nic.ru91.217.21.20
ns4-cloud.nic.ru89.104.93.30
ns8-cloud.nic.ru89.104.95.36
ns3-l2.nic.ru193.232.146.1

Mail servers (MX)

MX records point to the servers that receive e-mails sent to the domain, that is to @sk.ru addresses. Each server has a priority: the one with the lowest number is tried first, the others take over if it fails. Without an MX record, the domain cannot receive e-mails.

PriorityServerIP address
10mx7.sk.ru5.252.65.39
10mx8.sk.ru5.252.65.40

TXT records

TXT records hold free text. They are used to prove ownership of the domain to online services (Google, Microsoft, Facebook…) and to publish e-mail security rules: SPF on the domain itself, DMARC on _dmarc.sk.ru.

NameContent
sk.ruc661f5eb-7f54-428c-9509-2c668c11ebbb
sk.ruUXfcAMZbZWIFUjCY7AiqjKdmv309JRDkU3dvw/hG8B0cTAccMR1UMAh1DdSR+veWWRVCqfLvajqCeflquJewaw==
sk.ruglobalsign-domain-verification=6k5E1gFgVFyRoijJTswylNvM9l7loO2WC0KDikGLlF
sk.ruyandex-verification: c6f6284b2d13a862
sk.ru_globalsign-domain-verification=OzV37GS34imwAbqokvkqcJcuBBbsPpUiT7IgxLoYih
sk.ru202104242125030v9ngg43hnwpyyc4tgaxe9q5v3rhzvkns04cwhn6lewsyloqne
sk.ruglobalsign-domain-verification=Pk_JJ_crZc1vlvVK1dFw25TtvILlnTUJLsuDV-4_ID
sk.ru202006252129345t0yav38mnw7z041bc43jyetpsdsxyx9x4j9h237bj61173n0n
sk.ruglobalsign-domain-verification=_k102PuRPgRYPehyLLMlFSdgXV3Bclh43URCnJbdRM
sk.ruMS=ms38671341
sk.ru610aa30b-6b0c-48ca-98cf-060be35beaaa
sk.rucisco-ci-domain-verification=6de354eba4c380a41c31c1dcdc0bbfe6f577b05a6300f105d8b388ad67c0a27a
sk.rurm_verify=21b483f011
sk.rugoogle-site-verification=BzQaj1Oulp-oSwNpLepp9I8KXupMWcVF9LhJXwLakyQ
sk.ru2021082921200400h9lqdim0gf94as611cqv94ulu4jgg65i4uym8mrhyzdaap2i
sk.rutci-dcv=1aa3baf673c202ec532aa15c1e190d6a7aa1dc1df58578ba6d5b6fa9349ea2ae
sk.ruglobalsign-domain-verification=aqSHbRDcm3gUWmQGOPoTVSiRsanSU-a0oZowB5ZqKc
sk.ru202108062119045ds8in7kow7tsm9tv625y1f8gt60y276h8mfdxoxwefx3k11zs
sk.ruMS=ms19458122
sk.ruv=spf1 mx ip4:95.213.155.52 ip4:91.224.82.158 ip4:5.252.65.112 ip4:77.108.80.184 ip4:5.252.64.96 ip4:5.252.64.121 ip4:95.213.210.180 ip4:5.252.65.37 ip4:5.252.65.38 ip4:5.252.64.197 ip4:5.252.65.116 include:spf.unisender.com ~all
sk.ruZOOM_verify_cM0WwRu0dCxZz3JkvOuINh
sk.ruglobalsign-domain-verification=Cw6TnA-beHGpQMTTGVfmIJVrqtPeLx2hJr49TelTyf
sk.ruglobalsign-domain-verification=ZV7ve8jkKWd4IU2G605cxuFY9JXXRHCWbuUnd9Jl6x
sk.ruglobalsign-domain-verification=kZgkc0kicXHqxyO5p-WMj7rtoJjFA76Wb8gp1Ajkpa
sk.ru_globalsign-domain-verification=vAauz3NP7WvYQDkX36gDCPANSnBK6CgmCvbHPv-6gm
sk.ru202108201312034d4et7zilfj5f0nw453gerb4cn6d6ywcbymctnin1by60t02yn
sk.ru_globalsign-domain-verification=sVUR2bLKLEdZRNcI5UrXRQER4Tc3Zb_zVcmhJSnHoG
sk.ruyandex-verification: 4952f415e4567f46
sk.rumailru-verification: ff695be602fabc45
sk.ruyandex-verification: 4c7cb38c32b8278f
_dmarc.sk.ruv=DMARC1; p=quarantine; sp=quarantine; rua=mailto:[email protected]; ruf=mailto:[email protected]; fo=1
smtp._domainkey.sk.ruv=DKIM1; k=rsa; s=email; p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAub/++0a6fDTS6427Jm/+XQnoSkrKDYZ9Vd1n8TP5ed3eMy/vnxktdE3T/NqbP1H2czUIP7AI14C2We502RuYeeVMwRN0W9Id+9vob50O9qOFbWFbWJ2aNclLFPM7ymJY3amaNMf27fxjzDTLjQsHei66T1EClY8UvcetQi2wROOTfUf21VcWLCCF0L0q2jGOMApOgQGRyeEUYZO3n20yAMF4gq3zxe9Ngmr6TqDu5jiJpHqr6NXbBD0Y2NckMl1oEj3alBABXFXoO1L+667rFYTfKZUncP13MIO6GKbpLkHq289VxAr5RoB8mu5VNPbCM7zy6Fi1bjgPvmwqo6V7xwIDAQAB

Related IP addresses

IPv4 addresses used by sk.ru: website, name servers, mail servers and senders authorized by SPF.

IP addressUsed for/24 block
91.221.164.121Website91.221.164.0/24
91.217.20.20Name server ns4-l2.nic.ru91.217.20.0/24
91.217.21.20Name server ns8-l2.nic.ru91.217.21.0/24
89.104.93.30Name server ns4-cloud.nic.ru89.104.93.0/24
89.104.95.36Name server ns8-cloud.nic.ru89.104.95.0/24
193.232.146.1Name server ns3-l2.nic.ru193.232.146.0/24
5.252.65.39Mail server mx7.sk.ru5.252.65.0/24
5.252.65.40Mail server mx8.sk.ru5.252.65.0/24
95.213.155.52Authorized by SPF95.213.155.0/24
91.224.82.158Authorized by SPF91.224.82.0/24
5.252.65.112Authorized by SPF5.252.65.0/24
77.108.80.184Authorized by SPF77.108.80.0/24
5.252.64.96Authorized by SPF5.252.64.0/24
5.252.64.121Authorized by SPF5.252.64.0/24
95.213.210.180Authorized by SPF95.213.210.0/24
5.252.65.37Authorized by SPF5.252.65.0/24
5.252.65.38Authorized by SPF5.252.65.0/24
5.252.64.197Authorized by SPF5.252.64.0/24
5.252.65.116Authorized by SPF5.252.65.0/24

WHOIS of the domain sk.ru

% TCI Whois Service. Terms of use:
% https://tcinet.ru/documents/whois_ru_rf.pdf (in Russian)
% https://tcinet.ru/documents/whois_su.pdf (in Russian)

domain:        SK.RU
nserver:       ns3-l2.nic.ru.
nserver:       ns4-l2.nic.ru.
nserver:       ns8-l2.nic.ru.
state:         REGISTERED, DELEGATED, VERIFIED
org:           
taxpayer-id:   
registrar:     RU-CENTER-RU
admin-contact: https://www.nic.ru/whois
created:       2000-03-31T14:27:35Z
paid-till:     2027-04-30T21:00:00Z
free-date:     2027-06-01
source:        TCI

Last updated on 2026-10-01T04:38:01Z

% Query time: 382 msec
% WHEN: Thu Oct 01 04:42:35 UTC 2026