Summary
- Registrar
- —
- Status
- Created on
- April 24, 1985
- Expires on
- July 31, 2027
- Name servers
- NSAUTH1.NET.cmu.edu, NSAUTH2.NET.cmu.edu, NSAUTH3.NET.cmu.edu
- Mail servers
- ASPMX.L.GOOGLE.COM, ALT1.ASPMX.L.GOOGLE.COM, ALT2.ASPMX.L.GOOGLE.COM, ALT4.ASPMX.L.GOOGLE.COM, ALT3.ASPMX.L.GOOGLE.COM
- DMARC
- Monitoring
- SPF
- Soft
- DKIM
- 4 keys found
- Website
- See the website
Spoofing protection (DMARC)
E-mails spoofing this domain are only reported, not blocked.
DMARC tells mail servers what to do with an e-mail that claims to come from cmu.edu but fails SPF and DKIM checks.
- Policy
- Monitoring
- Subdomain policy
- Monitoring
- Messages covered
- 100%
- DKIM alignment
- Relaxed
- SPF alignment
- Relaxed
- Aggregate reports
- [email protected]
- Failure reports
- —
Record
v=DMARC1;p=none;sp=none;rua=mailto:[email protected]
Authorized senders (SPF)
E-mails sent by any other server are accepted but flagged as suspicious.
SPF lists the servers allowed to send e-mails for cmu.edu.
| Rule | Value | Result |
|---|---|---|
| include | _spf.cmu.edu | Allowed |
| all | — | Suspicious |
Top-level DNS lookups: 1 of 10 allowed
Record
v=spf1 include:_spf.cmu.edu ~all
E-mail signing (DKIM)
DKIM keys published by cmu.edu under the most common selectors. Other keys may exist under selectors specific to each sending service.
| Selector | Likely service | Key | Status |
|---|---|---|---|
| k2 | Mailchimp | RSA 2048 bits | Active |
| k3 | Mailchimp | RSA 2048 bits | Active |
| s1 | SendGrid | RSA 2048 bits | Active |
| s2 | SendGrid | RSA 1024 bits · short | Active |
RSA keys shorter than 2048 bits, called short keys, are discouraged: they are easier to break.
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 cmu.edu arrive; SPF, DKIM and DMARC let mail servers check that an e-mail claiming to come from cmu.edu 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 @cmu.edu 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
cmu.edu MX 10 mx1.cmu.edu. cmu.edu MX 20 mx2.cmu.edu.
What the record contains
- 10, 20
- Priority: the server with the lowest number is tried first. Servers with equal priority share the load.
- mx1.cmu.edu.
- 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
cmu.edu 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.cmu.edu, 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.cmu.edu 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.cmu.edu, 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.cmu.edu 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 cmu.edu
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 | 128.2.42.10 |
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 |
|---|---|
| NSAUTH1.NET.cmu.edu | 128.2.1.8 |
| NSAUTH2.NET.cmu.edu | 128.237.148.168 |
| NSAUTH3.NET.cmu.edu | 3.33.150.209 |
Mail servers (MX)
MX records point to the servers that receive e-mails sent to the domain, that is to @cmu.edu 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.
| Priority | Server | IP address |
|---|---|---|
| 1 | ASPMX.L.GOOGLE.COM | 64.233.184.27 |
| 5 | ALT1.ASPMX.L.GOOGLE.COM | 192.178.213.27 |
| 5 | ALT2.ASPMX.L.GOOGLE.COM | 142.251.127.26 |
| 10 | ALT4.ASPMX.L.GOOGLE.COM | 142.250.147.26 |
| 10 | ALT3.ASPMX.L.GOOGLE.COM | 172.253.148.27 |
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.cmu.edu.
| Name | Content |
|---|---|
| cmu.edu | [NRDR 34068_IN_TXT_atlassian-domain-verification=H4RHVEsTq5YZaRen7VBly2a3AqWhfLMxAL3wBScS8EB0Pg5x1vaPhj3eXsGaUOGi ePUw4Mw9giYZRVzpV/ysvQ] |
| cmu.edu | [NRDR 32847_IN_TXT_facebook-domain-verification=vxpo0xkores42yfj9ggcdd2o2d2v2n 9I1LCDr7zb+jK0IoSEFayA] |
| cmu.edu | [NRDR 31057_IN_TXT_00df4000000231leaa QSq9rQj5GCBh30pVnLGMtQ] |
| cmu.edu | EECD69320F38F645362247248BD675F4 |
| cmu.edu | [NRDR AN-23811_IN_A_128.2.42.10 JRwwvtp22mouAVo7Ye6sJQ] |
| cmu.edu | v=spf1 include:_spf.cmu.edu ~all |
| cmu.edu | [NRDR 36125_IN_TXT_e2ma-verification=fu2 tn9dGsCpd6YZrmWG6O9dqw] |
| cmu.edu | zoho-verification=zb38550127.zmverify.zoho.com |
| cmu.edu | [NRDR 37683_IN_TXT_A8809FFAB54BD9C6F7DFBE92616764D0 1pWIIBS0QK7rR0bt/OqwZg] |
| cmu.edu | google-site-verification=O2gyijlOW-8BSOghh0tL_4N1PlWU_qznkYhUA22dLJ0 |
| cmu.edu | [NRDR 34436_IN_TXT_google-site-verification=MYZf5OssFVvgYQF1snvJdiFbMjHy53WzLrnsVGkgpFU C0YNNkwQ5Qfm8taSZKc+1A] |
| cmu.edu | [NRDR 37587_IN_TXT_EECD69320F38F645362247248BD675F4 vdnDjzc5a9LVXuQ6DmgOhA] |
| cmu.edu | airtable-verification=878daeee4665d51015a6dda912bbb9f5 |
| cmu.edu | [NRDR 32936_IN_TXT_r4bgkix7EqRv+dJHKYelMrye44oR+366MsSA0lCP0TOcMK8wfs0bpTMDP1tLTZ66OFh0Qx+ZMLBCeVx0NJ3syQ== tGCEAk5qNOFhWjjp1w58vw] |
| cmu.edu | [NRDR 33014_IN_TXT_ZOOM_verify_FruZuJfdTeW1OOezpsuIVA +31oybl7gh2i74ky0SLQcg] |
| cmu.edu | [NRDR 36038_IN_TXT_cisco-ci-domain-verification=5f809f49f9d3ca48d84db537e031b2007011ea11f6410de6a8a02919908675d6 VTvqYpCLdM5K6bM5zRNwDQ] |
| cmu.edu | [NRDR 33356_IN_TXT_MS=ms17583017 io8/1MnXyp5PTqiijD8s0Q] |
| cmu.edu | [NRDR 34503_IN_TXT_google-site-verification=JopPlnNv9VupQydpE3TiwZAEod-zouxEX0inao6rggg HxtpS+uc1I0HuPBMBaTlCA] |
| cmu.edu | [NRDR 35458_IN_MX_10.ALT3.ASPMX.L.GOOGLE.COM. lw7k2ZT1H96ItGwU98g8LA] |
| cmu.edu | [NRDR 31504_IN_TXT_v=spf1.include:_spf.cmu.edu.~all jxEj2x9CC1Gu8ePZldY84w] |
| cmu.edu | reftab-domain-verification=c24d073b23fed3af77c9e3b40010223f |
| cmu.edu | [NRDR 35457_IN_MX_5.ALT2.ASPMX.L.GOOGLE.COM. pzqzxDk39X4PeiVpV+EvZQ] |
| cmu.edu | [NRDR 34437_IN_TXT_google-site-verification=m3lUupwhWqjbGCA6JswqWyBi7tkzh-BjbRiYuC6EXTg Or5AmLIb59AN+oiEMjOqoA] |
| cmu.edu | [NRDR 35455_IN_MX_1.ASPMX.L.GOOGLE.COM. JRKEGqRjzSnACLafB7QQiw] |
| cmu.edu | google-site-verification=MYZf5OssFVvgYQF1snvJdiFbMjHy53WzLrnsVGkgpFU |
| cmu.edu | [NRDR 34438_IN_TXT_google-site-verification=pNbrq7j_EeIowr_Kw1Jfy46bmFWR9p1llXH_leCdLrg eMgkItPzPonrYzRZBOx13w] |
| cmu.edu | [NRDR 34190_IN_TXT_docusign=048da45a-23c6-4f6b-8f96-6dff4fa6b22b AWGRCMvgvpXmHSJ7nxKghg] |
| cmu.edu | [NRDR 37284_IN_TXT_airtable-verification=878daeee4665d51015a6dda912bbb9f5 GCXTwRluJG0dSxHBUrbFYA] |
| cmu.edu | [NRDR 36124_IN_TXT_e2ma-verification=fu2 tn9dGsCpd6YZrmWG6O9dqw] |
| cmu.edu | [NRDR 34441_IN_TXT_zoho-verification=zb38550127.zmverify.zoho.com sbctKhpo8bhwlNq+f0khtw] |
| cmu.edu | google-site-verification=m3lUupwhWqjbGCA6JswqWyBi7tkzh-BjbRiYuC6EXTg |
| cmu.edu | r4bgkix7EqRv+dJHKYelMrye44oR+366MsSA0lCP0TOcMK8wfs0bpTMDP1tLTZ66OFh0Qx+ZMLBCeVx0NJ3syQ== |
| cmu.edu | google-site-verification=JopPlnNv9VupQydpE3TiwZAEod-zouxEX0inao6rggg |
| cmu.edu | facebook-domain-verification=vxpo0xkores42yfj9ggcdd2o2d2v2n |
| cmu.edu | google-site-verification=pNbrq7j_EeIowr_Kw1Jfy46bmFWR9p1llXH_leCdLrg |
| cmu.edu | A8809FFAB54BD9C6F7DFBE92616764D0 |
| cmu.edu | [NRDR 16337_IN_LOC_40.26.39.0.N.79.56.36.2.W.283.1.10.10 5PS/aNXhz6qcZ6tfoRdgeQ] |
| cmu.edu | atlassian-domain-verification=H4RHVEsTq5YZaRen7VBly2a3AqWhfLMxAL3wBScS8EB0Pg5x1vaPhj3eXsGaUOGi |
| cmu.edu | docusign=048da45a-23c6-4f6b-8f96-6dff4fa6b22b |
| cmu.edu | 00df4000000231leaa |
| cmu.edu | MS=ms17583017 |
| cmu.edu | [NRDR 30017_IN_TXT_google-site-verification=O2gyijlOW-8BSOghh0tL_4N1PlWU_qznkYhUA22dLJ0 PiRIS0yTtnNYmTWYpWCCVw] |
| cmu.edu | cisco-ci-domain-verification=5f809f49f9d3ca48d84db537e031b2007011ea11f6410de6a8a02919908675d6 |
| cmu.edu | apple-domain-verification=yZrPHuazhdH42CPf |
| cmu.edu | [NRDR 34415_IN_TXT_apple-domain-verification=yZrPHuazhdH42CPf dbWBQEISZeHDi/9KkKT96g] |
| cmu.edu | [NRDR 37073_IN_TXT_reftab-domain-verification=c24d073b23fed3af77c9e3b40010223f Kmo0sQxn82COz9etYwP/3w] |
| cmu.edu | [NRDR 35456_IN_MX_5.ALT1.ASPMX.L.GOOGLE.COM. /CTPCIrZ0nFHanr+3VJRfw] |
| cmu.edu | [NRDR 35459_IN_MX_10.ALT4.ASPMX.L.GOOGLE.COM. EkBzBKUeTsTJg2w4Ly2bMw] |
| cmu.edu | e2ma-verification=fu2 |
| cmu.edu | ZOOM_verify_FruZuJfdTeW1OOezpsuIVA |
| _dmarc.cmu.edu | v=DMARC1;p=none;sp=none;rua=mailto:[email protected] |
| k2._domainkey.cmu.edu | v=DKIM1; k=rsa; p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAv2aC2KjGKLOwTweBY5A9RpjsxaBXR9r7OAU6U8/zn92ivImI75naUujWbItRI/QmL1jy5PWGqLwoUA0b90ObWaLDc+i9MtTNmGeWO009hr20fIxhGg6XBT2kjZ1DTThopSe1nAndsupmcBwlQ5Q6LJ+ZAxLcujnPIxM0ZBLmgpkv8u6RfY4eFP8OLvdAW3oSuB0DyLDigQX4Sj8wBO4YIdQH6AAmBeOsidsKAFNFUCpc3vCxtBDR12U+cBg724l3sBkMQ8evnz6idnqxq9QAVYh8k4kJ+RP+6cqTdy7LjIm8xY/bQNpQIpGUAuDo2DjLcCDun9DAI4Q/3z+Q0o9QuQIDAQAB; |
| k3._domainkey.cmu.edu | v=DKIM1; k=rsa; p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAsYGiMSn7fsUqSvfSX40x9R1OlRtbNiCY80lHRIlcKx3XDIR7257aUx+q9CSIARdfTL6KCuLGNFx5g9TgVr6png4ajcieSQGtOehBgxnkDN8aAA5TX0FmFrcefJU0JoxLOF09EKgXxhSSHCk/ekVb0PXSboHXoZ9+EI404F1qhcwXXIgHXTaUthHTut2P6BBZhIXIgvDe/w49GchR7MRJqjNb7neEBbYHbgWuBTvvHCg7Gy6m6n9krYK+ROWq3dVvXy9plAGK3ygM+HtjIiMt7arRGMOF0WgDTz7YdN9BGpt6BvXxLnjiQcgS5T9n+cIyPZgiWzDMXNlaEEdKTEKxrwIDAQAB; |
| s1._domainkey.cmu.edu | k=rsa; t=s; p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA1CJ6+q+N264DhEGxi92ISXCkZT+f06yc1eGBSwtRDqew9YFF9HoanGe8uEoPsUZhxP7dIIxktbM+/k4CnSgowyP+a82oMp/IzNueGSmN/mBD+v2NzYGctHBAQirflHsXncWhyW1vIJwB5YUoxqNHIGn+fI0EDyGl9bxBdP6CCaSUumGF3o95CWKuQa8N7LSikzVjNTBs1MQ0zIzUaDtP8Oejbai3x+Gallld+4jL9PkBIzzsH7tt1XjWSBcKVUBSjwBvkdohwdLHreNxHkV1wtmvhDzbnf5RSsd9i9wYYzzgmb8pJ/w58YyaEpVMieV5mgxFjD3x8mXUICC3e3dEBwIDAQAB |
| s2._domainkey.cmu.edu | k=rsa; t=s; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDTUzQVpQ1SATUnikEo0S3AEJl3+2Q5ygaEhH44gXT175xTyqMXwmS09OkVX7RP11M0ZW55c3v+adhzNNrAQhD3aZnAJ2Wnedsf+aRH6IvBkCx6jAcD90jR739ua+3SZR+8sbgcBj83CjBm7Em1sSSb3mcVgmTwc0EKaTQwbk49YwIDAQAB |
Related IP addresses
IPv4 addresses used by cmu.edu: website, name servers, mail servers and senders authorized by SPF.
| IP address | Used for | /24 block |
|---|---|---|
| 128.2.42.10 | Website | 128.2.42.0/24 |
| 128.2.1.8 | Name server NSAUTH1.NET.cmu.edu | 128.2.1.0/24 |
| 128.237.148.168 | Name server NSAUTH2.NET.cmu.edu | 128.237.148.0/24 |
| 3.33.150.209 | Name server NSAUTH3.NET.cmu.edu | 3.33.150.0/24 |
| 64.233.184.27 | Mail server ASPMX.L.GOOGLE.COM | 64.233.184.0/24 |
| 192.178.213.27 | Mail server ALT1.ASPMX.L.GOOGLE.COM | 192.178.213.0/24 |
| 142.251.127.26 | Mail server ALT2.ASPMX.L.GOOGLE.COM | 142.251.127.0/24 |
| 142.250.147.26 | Mail server ALT4.ASPMX.L.GOOGLE.COM | 142.250.147.0/24 |
| 172.253.148.27 | Mail server ALT3.ASPMX.L.GOOGLE.COM | 172.253.148.0/24 |
WHOIS of the domain cmu.edu
This Registry database contains ONLY .EDU domains. The data in the EDUCAUSE Whois database is provided by EDUCAUSE for information purposes in order to assist in the process of obtaining information about or related to .edu domain registration records. The EDUCAUSE Whois database is authoritative for the .EDU domain. A Web interface for the .EDU EDUCAUSE Whois Server is available at: http://whois.educause.edu By submitting a Whois query, you agree that this information will not be used to allow, enable, or otherwise support the transmission of unsolicited commercial advertising or solicitations via e-mail. The use of electronic processes to harvest information from this server is generally prohibited except as reasonably necessary to register or modify .edu domain names. ------------------------------------------------------------- Domain Name: CMU.EDU Registrant: Carnegie Mellon University Cyert Hall 216 5000 Forbes Avenue Pittsburgh, PA 15213 USA Administrative Contact: Host Master Carnegie Mellon University Cyert Hall 215 5000 Forbes Ave Pittsburgh, PA 15213-3890 USA +1.4122684357 [email protected] Technical Contact: Host Master Carnegie Mellon University Cyert Hall 215 5000 Forbes Ave Pittsburgh, PA 15213-3890 USA +1.4122684357 [email protected] Name Servers: NSAUTH3.NET.CMU.EDU NSAUTH2.NET.CMU.EDU NSAUTH1.NET.CMU.EDU Domain record activated: 24-Apr-1985 Domain record last updated: 30-Jan-2026 Domain expires: 31-Jul-2027 % Query time: 533 msec % WHEN: Fri Oct 02 03:16:34 UTC 2026