aws.dev
At risk, with 3 things to fix
aws.dev scored 32/100 (grade F). The main issues are no MX records and no DKIM key found for the common selectors, plus 2 more.
Checked 2026-10-04 02:03 UTC · fresh check
Strengthen the DMARC policy
Rejects mail that fails DMARC, the strongest protection against spoofing. Changes: Subdomains move one step, from sp=none to sp=quarantine.
_dmarc.aws.dev
Some DNS providers want just “_dmarc” here.
v=DMARC1; p=reject; sp=quarantine; rua=mailto:report@dmarc.amazon.com; adkim=r; aspf=r
v=DMARC1; p=reject; sp=none; rua=mailto:report@dmarc.amazon.com; ruf=mailto:report@dmarc.amazon.com
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 MX recordsFailing
- Fail: No MX records
aws.dev has no MX records and no A/AAAA fallback, so it cannot receive mail, including bounces and DMARC reports. Publish an MX record pointing at your mail provider.
SPFWho may send as you?No issues foundPass
Nothing to report.
DKIMAre your emails signed?No DKIM key found for the common selectorsNeeds attention
- Warning: No DKIM key found for the common selectors
None of the 47 selectors probed under aws.dev publish a DKIM key. DNS cannot list selectors, so a key under a custom selector may exist: find the s= value in the DKIM-Signature header of a message you sent and check that selector. If DKIM is not set up, enable it at each service that sends mail for aws.dev.
DMARCWhat happens to fakes?Subdomain policy is weaker than the domain policyNeeds attention
- Warning: Subdomain policy is weaker than the domain policy
sp=none is weaker than p=reject, so attackers can spoof any subdomain of aws.dev (for example billing.aws.dev) even though the main domain is protected.
How to fix this - Warning: External DMARC report address is not authorized
Reports go to dmarc.amazon.com, which is outside aws.dev. RFC 7489 requires that domain to publish a valid v=DMARC1 TXT record at aws.dev._report._dmarc.dmarc.amazon.com; without it receivers will not send you aggregate reports. Your report provider normally publishes this for you.
AlignmentDoes it match your From?SPF alignment is unknownInfo
- Info: SPF alignment is unknown
The SPF record of aws.dev authorizes no sender (no +ip4, +ip6, +a, +mx, +exists or +ptr term, include of a record that has one, or +all before all), so SPF never passes and cannot align. That is correct for a domain that sends no mail; otherwise DMARC depends on DKIM alone.
BIMICan inboxes show your logo?No BIMI recordInfo
- Info: No BIMI record
No BIMI record at default._bimi.aws.dev. 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.aws.dev. MTA-STS (RFC 8461) makes sending servers require TLS and a valid certificate when delivering to you, which blocks downgrade attacks.
TLS-RPTWill you hear about failures?No TLS-RPT recordInfo
- Info: No TLS-RPT record
No TLS reporting record at _smtp._tls.aws.dev. TLS-RPT (RFC 8460) tells senders where to send daily reports about failed encrypted deliveries to you.
How to fix this
Other fixes
Set up a TLS report addressinstruction
Sending servers will report TLS failures when delivering to aws.dev, 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.aws.dev
- Pick an address that will receive TLS reports: a mailbox you read (for example tls-reports@aws.dev, created first) or a TLS reporting service. 2. Publish a TXT record at _smtp._tls.aws.dev 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.aws.dev
- 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://aws.dev/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.aws.dev with v=BIMI1, l= set to the logo URL and a= set to the certificate URL.