nasa.gov
Good, with 2 things to fix
nasa.gov scored 84/100 (grade B). The main issues are DKIM key shorter than 2048 bits and SPF is close to the 10-lookup limit. Detected senders: Microsoft 365.
Checked 2026-10-04 02:08 UTC · fresh check
Reduce SPF DNS lookups
Evaluating SPF for nasa.gov takes 9 DNS lookups including nested includes; receivers stop at 10 and fail SPF. No detected sending service accounts for these includes; remove each one you no longer send through: _spf-4a.nasa.gov, _spf-4b.nasa.gov, _spf-4c.nasa.gov, _spf-4d.nasa.gov, _spf-4g.nasa.gov, _spf-4m.nasa.gov, _spf-4x.nasa.gov, _spf-6a.nasa.gov.
nasa.gov
Some DNS providers want “@” here instead of the full domain.
v=spf1 include:_spf-4a.nasa.gov include:_spf-4b.nasa.gov include:_spf-4c.nasa.gov include:_spf-4d.nasa.gov include:_spf-4g.nasa.gov include:_spf-4m.nasa.gov include:_spf-4x.nasa.gov include:_spf-6a.nasa.gov include:spf.protection.outlook.com -all
v=spf1 include:_spf-4a.nasa.gov include:_spf-4b.nasa.gov include:_spf-4c.nasa.gov include:_spf-4d.nasa.gov include:_spf-4g.nasa.gov include:_spf-4m.nasa.gov include:_spf-4x.nasa.gov include:_spf-6a.nasa.gov include:spf.protection.outlook.com -all
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?Only one MX hostInfo
- Info: Only one MX host
All mail for nasa.gov goes to nasa-gov.mail.protection.outlook.com. Most hosted providers make that one name highly available; if you run your own server, consider a backup MX.
SPFWho may send as you?SPF is close to the 10-lookup limitNeeds attention
- Warning: SPF is close to the 10-lookup limit
Evaluating the SPF record for nasa.gov needs 9 of the 10 allowed DNS lookups. Adding one more service, or a provider growing its own record, will break SPF.
How to fix this
DKIMAre your emails signed?DKIM key shorter than 2048 bitsNeeds attention
- Warning: DKIM key shorter than 2048 bits
selector1 (1024-bit) uses an RSA key below 2048 bits. Short keys can be factored and some receivers treat them as weak. Rotate to a 2048-bit key at your sending provider.
- Pass: DKIM key published
nasa.gov publishes a DKIM key under selector1.
DMARCWhat happens to fakes?No issues foundPass
Nothing to report.
AlignmentDoes it match your From?No issues foundPass
Nothing to report.
BIMICan inboxes show your logo?No BIMI recordInfo
- Info: No BIMI record
No BIMI record at default._bimi.nasa.gov. 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.nasa.gov. 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.nasa.gov. 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 nasa.gov publishes an MTA-STS policy at https://mta-sts.nasa.gov/.well-known/mta-sts.txt. Change the id whenever the policy file changes.
_mta-sts.nasa.gov
Some DNS providers want just “_mta-sts” here.
v=STSv1; id=202610040208
Host the MTA-STS policy filepolicy-file
Serve this file over HTTPS with a valid certificate for mta-sts.nasa.gov. It lists your MX hosts and starts in testing mode; switch to mode: enforce once TLS-RPT reports show no failures.
https://mta-sts.nasa.gov/.well-known/mta-sts.txt
version: STSv1 mode: testing mx: nasa-gov.mail.protection.outlook.com max_age: 604800
Set up a TLS report addressinstruction
Sending servers will report TLS failures when delivering to nasa.gov, 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.nasa.gov
- Pick an address that will receive TLS reports: a mailbox you read (for example tls-reports@nasa.gov, created first) or a TLS reporting service. 2. Publish a TXT record at _smtp._tls.nasa.gov 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.nasa.gov
- 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://nasa.gov/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.nasa.gov with v=BIMI1, l= set to the logo URL and a= set to the certificate URL.