Summary
- Registrar
- MarkMonitor, Inc.
- Status
- clientUpdateProhibited
- Created on
- September 12, 2017
- Expires on
- September 13, 2027
- Name servers
- dns2.p02.nsone.net, dns3.p02.nsone.net, ns02.slackdns.com, ns03.slackdns.com, dns1.p02.nsone.net, ns04.slackdns.com, ns01.slackdns.com, dns4.p02.nsone.net
- Mail servers
- —
- SPF
- Strict
- DKIM
- No key found among the common selectors
- Website
- See the website
Authorized senders (SPF)
E-mails sent by any other server are rejected.
SPF lists the servers allowed to send e-mails for slack.design.
| Rule | Value | Result |
|---|---|---|
| all | — | Rejected |
Top-level DNS lookups: 0 of 10 allowed
Record
v=spf1 -all
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 slack.design arrive; SPF, DKIM and DMARC let mail servers check that an e-mail claiming to come from slack.design 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 @slack.design 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
slack.design MX 10 mx1.slack.design. slack.design MX 20 mx2.slack.design.
What the record contains
- 10, 20
- Priority: the server with the lowest number is tried first. Servers with equal priority share the load.
- mx1.slack.design.
- 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
slack.design 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.slack.design, 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.slack.design 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.slack.design, 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.slack.design 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 slack.design
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.
| Type | IP address |
|---|---|
| A | 192.0.66.216 |
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.
| Server | IP address |
|---|---|
| dns2.p02.nsone.net | 198.51.45.2 |
| dns3.p02.nsone.net | 198.51.44.66 |
| ns02.slackdns.com | 45.54.67.65 |
| ns03.slackdns.com | 45.54.67.129 |
| dns1.p02.nsone.net | 198.51.44.2 |
| ns04.slackdns.com | 45.54.67.193 |
| ns01.slackdns.com | 45.54.67.1 |
| dns4.p02.nsone.net | 198.51.45.66 |
Mail servers (MX)
MX records point to the servers that receive e-mails sent to the domain, that is to @slack.design 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.
No mail server: the domain does not receive e-mails.
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.slack.design.
| Name | Content |
|---|---|
| slack.design | v=spf1 -all |
Related IP addresses
IPv4 addresses used by slack.design: website, name servers, mail servers and senders authorized by SPF.
| IP address | Used for | /24 block |
|---|---|---|
| 192.0.66.216 | Website | 192.0.66.0/24 |
| 198.51.45.2 | Name server dns2.p02.nsone.net | 198.51.45.0/24 |
| 198.51.44.66 | Name server dns3.p02.nsone.net | 198.51.44.0/24 |
| 45.54.67.65 | Name server ns02.slackdns.com | 45.54.67.0/24 |
| 45.54.67.129 | Name server ns03.slackdns.com | 45.54.67.0/24 |
| 198.51.44.2 | Name server dns1.p02.nsone.net | 198.51.44.0/24 |
| 45.54.67.193 | Name server ns04.slackdns.com | 45.54.67.0/24 |
| 45.54.67.1 | Name server ns01.slackdns.com | 45.54.67.0/24 |
| 198.51.45.66 | Name server dns4.p02.nsone.net | 198.51.45.0/24 |
WHOIS of the domain slack.design
Domain Name: slack.design Registry Domain ID: REDACTED FOR PRIVACY Registrar WHOIS Server: whois.markmonitor.com Registrar URL: www.markmonitor.com Updated Date: 2026-02-24T01:33:04Z Creation Date: 2017-09-12T21:48:19Z Registry Expiry Date: 2027-09-12T23:59:59Z Registrar: MarkMonitor, Inc. Registrar IANA ID: 292 Registrar Abuse Contact Email: [email protected] Registrar Abuse Contact Phone: +1.2083895740 Domain Status: clientUpdateProhibited https://icann.org/epp#clientUpdateProhibited Domain Status: clientDeleteProhibited https://icann.org/epp#clientDeleteProhibited Domain Status: clientTransferProhibited https://icann.org/epp#clientTransferProhibited Registry Registrant ID: REDACTED FOR PRIVACY Registrant Name: REDACTED FOR PRIVACY Registrant Organization: Salesforce, Inc. Registrant Street: REDACTED FOR PRIVACY Registrant Street: REDACTED FOR PRIVACY Registrant Street: REDACTED FOR PRIVACY Registrant City: REDACTED FOR PRIVACY Registrant State/Province: CA Registrant Postal Code: REDACTED FOR PRIVACY Registrant Country: US Registrant Phone: REDACTED FOR PRIVACY Registrant Phone Ext: REDACTED FOR PRIVACY Registrant Fax: REDACTED FOR PRIVACY Registrant Fax Ext: REDACTED FOR PRIVACY Registrant Email: Please query the RDDS service of the Registrar of Record identified in this output for information on how to contact the Registrant, Admin, or Tech contact of the queried domain name. Registry Admin ID: Admin Name: Admin Organization: Admin Street: Admin Street: Admin Street: Admin City: Admin State/Province: Admin Postal Code: Admin Country: Admin Phone: Admin Phone Ext: Admin Fax: Admin Fax Ext: Admin Email: Registry Tech ID: REDACTED FOR PRIVACY Tech Name: REDACTED FOR PRIVACY Tech Organization: REDACTED FOR PRIVACY Tech Street: REDACTED FOR PRIVACY Tech Street: REDACTED FOR PRIVACY Tech Street: REDACTED FOR PRIVACY Tech City: REDACTED FOR PRIVACY Tech State/Province: REDACTED FOR PRIVACY Tech Postal Code: REDACTED FOR PRIVACY Tech Country: REDACTED FOR PRIVACY Tech Phone: REDACTED FOR PRIVACY Tech Phone Ext: REDACTED FOR PRIVACY Tech Fax: REDACTED FOR PRIVACY Tech Fax Ext: REDACTED FOR PRIVACY Tech Email: Please query the RDDS service of the Registrar of Record identified in this output for information on how to contact the Registrant, Admin, or Tech contact of the queried domain name. Name Server: dns2.p02.nsone.net Name Server: dns3.p02.nsone.net Name Server: dns4.p02.nsone.net Name Server: dns1.p02.nsone.net Name Server: ns02.slackdns.com Name Server: ns01.slackdns.com Name Server: ns04.slackdns.com Name Server: ns03.slackdns.com DNSSEC: unsigned URL of the ICANN Whois Inaccuracy Complaint Form: https://www.icann.org/wicf/ >>> Last update of WHOIS database: 2026-10-01T21:37:37Z <<< For more information on Whois status codes, please visit https://icann.org/epp The Service is provided so that you may look up certain information in relation to domain names that we store in our database. Use of the Service is subject to our policies, in particular you should familiarise yourself with our Acceptable Use Policy and our Privacy Policy. The information provided by this Service is 'as is' and we make no guarantee of it its accuracy. You agree that by your use of the Service you will not use the information provided by us in a way which is: * inconsistent with any applicable laws, * inconsistent with any policy issued by us, * to generate, distribute, or facilitate unsolicited mass email, promotions, advertisings or other solicitations, or * to enable high volume, automated, electronic processes that apply to the Service. You acknowledge that: * a response from the Service that a domain name is 'available', does not guarantee that is able to be registered, * we may restrict, suspend or terminate your access to the Service at any time, and * the copying, compilation, repackaging, dissemination or other use of the information provided by the Service is not permitted, without our express written consent. This information has been prepared and published in order to represent administrative and technical management of the TLD. We may discontinue or amend any part or the whole of these Terms of Service from time to time at our absolute discretion. Domain Name: slack.design Registry Domain ID: D52316524CNIC-GDREG Registrar WHOIS Server: whois.markmonitor.com Registrar URL: http://www.markmonitor.com Updated Date: 2026-02-24T01:33:04+0000 Creation Date: 2017-09-12T21:48:19+0000 Registrar Registration Expiration Date: 2027-09-12T00:00:00+0000 Registrar: MarkMonitor, Inc. Registrar IANA ID: 292 Registrar Abuse Contact: https://corp.markmonitor.com/domain/ui/abuse-report Registrar Abuse Contact Phone: +1.2086851750 Domain Status: clientUpdateProhibited (https://www.icann.org/epp#clientUpdateProhibited) Domain Status: clientTransferProhibited (https://www.icann.org/epp#clientTransferProhibited) Domain Status: clientDeleteProhibited (https://www.icann.org/epp#clientDeleteProhibited) Registrant Organization: Salesforce, Inc. Registrant Country: US Registrant Email: Select Request Email Form at https://domains.markmonitor.com/whois/slack.design Tech Name: Slack Hostmaster Tech Phone: +1.4158058989 Tech Email: [email protected] Name Server: ns04.slackdns.com Name Server: ns01.slackdns.com Name Server: dns3.p02.nsone.net Name Server: dns1.p02.nsone.net Name Server: dns2.p02.nsone.net Name Server: dns4.p02.nsone.net Name Server: ns02.slackdns.com Name Server: ns03.slackdns.com DNSSEC: unsigned URL of the ICANN WHOIS Data Problem Reporting System: http://wdprs.internic.net/ >>> Last update of WHOIS database: 2026-10-01T21:37:37+0000 <<< For more information on WHOIS status codes, please visit: https://www.icann.org/resources/pages/epp-status-codes If you wish to contact this domain’s Registrant or Technical contact, and such email address is not visible above, you may do so via our web form, pursuant to ICANN’s Temporary Specification. To verify that you are not a robot, please enter your email address to receive a link to a page that facilitates email communication with the relevant contact(s). Web-based WHOIS: https://domains.markmonitor.com/whois/contact/slack.design If you have a legitimate interest in viewing the non-public WHOIS details, send your request and the reasons for your request to [email protected] and specify the domain name in the subject line. We will review that request and may ask for supporting documentation and explanation. The data in MarkMonitor’s WHOIS database is provided for information purposes, and to assist persons in obtaining information about or related to a domain name’s registration record. While MarkMonitor believes the data to be accurate, the data is provided "as is" with no guarantee or warranties regarding its accuracy. By submitting a WHOIS query, you agree that you will use this data only for lawful purposes and that, under no circumstances will you use this data to: (1) allow, enable, or otherwise support the transmission by email, telephone, or facsimile of mass, unsolicited, commercial advertising, or spam; or (2) enable high volume, automated, or electronic processes that send queries, data, or email to MarkMonitor (or its systems) or the domain name contacts (or its systems). MarkMonitor reserves the right to modify these terms at any time. By submitting this query, you agree to abide by this policy. MarkMonitor Domain Management(TM) Protecting companies and consumers in a digital world. Visit MarkMonitor at https://www.markmonitor.com Contact us at +1.8007459229 In Europe, at +44.02032062220 % Query time: 1384 msec % WHEN: Thu Oct 01 21:37:36 UTC 2026