mayoclinic.org
Needs work, with 4 things to fix
mayoclinic.org scored 61/100 (grade C). The main issues are DMARC policy is none and DMARC alignment: DKIM alignment is unlikely under adkim=s, plus 2 more.
Checked 2026-10-04 02:19 UTC · fresh check
Strengthen the DMARC policy
Quarantines all mail that fails DMARC. Move on to reject once the reports stay clean. Changes: pct applies to sp as well, so a pct=25 ramp would enforce sp=reject on only a quarter of subdomain mail. The ramp is skipped to keep subdomains fully protected; p moves to quarantine directly.
_dmarc.mayoclinic.org
Some DNS providers want just “_dmarc” here.
v=DMARC1; p=quarantine; sp=reject; rua=mailto:dmarc-summary@mayo.edu; adkim=s; aspf=s
v=DMARC1; p=none; sp=reject; pct=100; rf=afrf; ri=86400; fo=1; aspf=s; adkim=s; ruf=mailto:dmarc-details@mayo.edu; rua=mailto:dmarc-summary@mayo.edu
How to apply it
- Sign in where your domain’s DNS is managed. This is often where you bought the domain, such as Cloudflare, GoDaddy or Namecheap.
- Find the existing TXT record with that name and replace its value.
- Save, then come back and re-check. DNS changes can take up to a few hours to show.
All checks
MXCan servers find your inbox?No issues foundPass
Nothing to report.
SPFWho may send as you?SPF has too many lookups that return nothingNeeds attention
- Warning: SPF has too many lookups that return nothing
Checking mail from mayoclinic.org, IPv6 clients would hit 8 void lookups (DNS queries that return no data). RFC 7208 lets receivers fail SPF after 2. Remove includes and mechanisms that point at names that no longer exist, or MX hosts without an address for that family.
DKIMAre your emails signed?DKIM record cannot be parsedNeeds attention
- Warning: DKIM record cannot be parsed
ses: p= is not an RSA public key (SubjectPublicKeyInfo or RSAPublicKey). Receivers ignore a record they cannot parse, so mail signed with it fails DKIM. Copy the record again from your provider.
DMARCWhat happens to fakes?DMARC policy is noneNeeds attention
- Warning: DMARC policy is none
A none policy only monitors: mail that fails DMARC is still delivered, so anyone can spoof the domain. Once reports show your legitimate senders pass, move to quarantine and then reject.
How to fix this - Info: DMARC uses strict alignment
With adkim=s or aspf=s the DKIM d= domain or the bounce domain must equal the From domain exactly; a subdomain is not enough. Third-party senders that sign or bounce from a subdomain (or their own domain) will then fail DMARC unless they are configured to use your exact domain.
AlignmentDoes it match your From?DKIM alignment is unlikely under adkim=sNeeds attention
- Warning: DKIM alignment is unlikely under adkim=s
This is a heuristic. No DKIM key was found at mayoclinic.org under the selectors we probed, and adkim=s requires the signing d= domain to equal mayoclinic.org exactly. If your mail is signed with a provider's domain or a subdomain, DKIM will not align. A key may exist under a selector we did not try; send a test message to confirm.
- Info: SPF alignment is unknown
The SPF record of mayoclinic.org can pass for some senders (those matched before the failing part), but another evaluation path ends in a permanent error (spf.void-lookups). Senders that reach that path fail SPF, so whether your mail aligns through SPF is unknown. Fix the error so every path evaluates.
BIMICan inboxes show your logo?No BIMI recordInfo
- Info: No BIMI record
No BIMI record at default._bimi.mayoclinic.org. BIMI is optional: it shows your logo next to your mail in supporting inboxes once DMARC is enforced.
How to fix this
MTA-STSIs mail to you encrypted?No MTA-STS recordInfo
- Info: No MTA-STS record
No MTA-STS record at _mta-sts.mayoclinic.org. MTA-STS (RFC 8461) makes sending servers require TLS and a valid certificate when delivering to you, which blocks downgrade attacks.
How to fix this
TLS-RPTWill you hear about failures?No TLS-RPT recordInfo
- Info: No TLS-RPT record
No TLS reporting record at _smtp._tls.mayoclinic.org. TLS-RPT (RFC 8460) tells senders where to send daily reports about failed encrypted deliveries to you.
How to fix this
Other fixes
Publish the MTA-STS recordTXT
Tells sending servers that mayoclinic.org publishes an MTA-STS policy at https://mta-sts.mayoclinic.org/.well-known/mta-sts.txt. Change the id whenever the policy file changes.
_mta-sts.mayoclinic.org
Some DNS providers want just “_mta-sts” here.
v=STSv1; id=202610040219
Host the MTA-STS policy filepolicy-file
Serve this file over HTTPS with a valid certificate for mta-sts.mayoclinic.org. It lists your MX hosts and starts in testing mode; switch to mode: enforce once TLS-RPT reports show no failures.
https://mta-sts.mayoclinic.org/.well-known/mta-sts.txt
version: STSv1 mode: testing mx: mail2.mayo.edu mx: mail3.mayo.edu mx: mail4.mayo.edu mx: mail5.mayo.edu max_age: 604800
Set up a TLS report addressinstruction
Sending servers will report TLS failures when delivering to mayoclinic.org, which you need before enforcing MTA-STS. The address must accept TLS reports; a DMARC report address does not necessarily do so.
Applies to: _smtp._tls.mayoclinic.org
- Pick an address that will receive TLS reports: a mailbox you read (for example tls-reports@mayoclinic.org, created first) or a TLS reporting service. 2. Publish a TXT record at _smtp._tls.mayoclinic.org with the value v=TLSRPTv1; rua=mailto:<that address>.
Prepare BIMIinstruction
BIMI shows your logo next to messages in supporting inboxes, but only for mail that passes DMARC under an enforced policy.
Applies to: default._bimi.mayoclinic.org
- Enforce DMARC first: p=quarantine or p=reject at 100% (no pct below 100). 2. Convert your logo to an SVG Tiny PS file and host it over HTTPS, for example https://mayoclinic.org/bimi/logo.svg. 3. For Gmail and Apple Mail, obtain a VMC or CMC certificate for the logo. 4. Publish a TXT record at default._bimi.mayoclinic.org with v=BIMI1, l= set to the logo URL and a= set to the certificate URL.