InboxAudit

caltech.edu email records

What caltech.edu publishes in public DNS for SPF, DKIM, DMARC, MX and BIMI, resolved on 2026-08-04.

SPF

v=spf1 ip4:131.215.0.0/16 ip4:134.4.0.0/16 ip4:192.100.16.0/24 ip4:198.129.208.0/23 ip4:208.69.128.0/22 ip4:199.188.184.0/22 ip4:198.202.125.128/25 ip4:74.122.104.0/22 ip4:72.10.184.102 ip4:72.10.184.103 ip4:72.10.182.15 ip4:72.10.182.16 include:spf.protection.outlook.com include:sendgrid.net include:mktomail.com include:spf.dynect.net include:cust-spf.cashnet.com include:amazonses.com include:_spf.createsend.com include:_spf01.mykronos.com include:_s0.caltech.edu ?all
10 of 10 DNS lookups — close to the limit.

The record authorises these sending platforms: Microsoft 365, Twilio SendGrid, Adobe Marketo Engage, Resend.

DMARC

v=DMARC1; p=none; rua=mailto:6e39dba0@mxtoolbox.dmarc-report.com,mailto:caltech@us.cp-dmarc.com; ruf=mailto:6e39dba0@forensics.dmarc-report.com,mailto:caltech@us.cp-dmarc.com; fo=1
policy
p=none
applies to
100% of mail
reports
mailto:6e39dba0@mxtoolbox.dmarc-report.com,mailto:caltech@us.cp-dmarc.com
alignment
adkim=r, aspf=r

DKIM

Keys found on 4 of 10 probed selectors:

selector1selector2defaults1

MX

mx1.caltech.iphmx.commx2.caltech.iphmx.com

Notes on this configuration

SPF uses exactly 10 of the 10 permitted DNS lookups. It is valid, but has no headroom.
SPF ends in ?all (neutral), which asserts nothing.
DMARC policy is p=none, which only monitors and blocks nothing.

Check it live

The above is a snapshot from 2026-08-04. Re-resolve it now: