linode.com
Receivers are told to reject mail that fails authentication for this domain.
Receivers are told to reject mail that fails authentication for this domain. Keep watching aggregate reports so a new sending service does not silently start failing.
Score held up: DMARC is enforcing at p=reject, so nobody else can send as this domain. That is the hard part, and it is done. What is left below is about your own mail arriving, not about anyone spoofing you.
142 DNS queries · 3756 ms
- 1Could not verify DKIM signing for Google WorkspaceConfirm DKIM is switched on in Google Workspace, then add your selector here so every future scan can verify it directly.
- 2Selector 'm1' uses a 1024-bit RSA keyRotate to 2048-bit at your next key rotation.
- 3No CAA recordPublish a CAA record naming your certificate authority, for example: 0 issue "letsencrypt.org"
- 4No MTA-STS policyPublish a TXT record at _mta-sts.linode.com and a policy file at https://mta-sts.linode.com/.well-known/mta-sts.txt.
Identity ·Sending services detected
Read from your SPF includes and MX hosts, then checked for a published DKIM key.
Identity ·DMARC
- Policy
- reject
- Coverage
- 100%
- Alignment
- dkim=r spf=r
Identity ·DKIM
111 selectors probed
m1MarketoRSA 1024k1Mailchimp / MailgunRSA 2048Identity ·SPF
Worst-case evaluation across every include.
- include:sendersv4b.mail.linode.com
- include:_spf.google.com
- include:mktomail.com
- include:spf-009e7401.pphosted.com
Findings (7)
MediumCould not verify DKIM signing for Google Workspace›
Google Workspace was detected via SPF include:_spf.google.com, so it is authorised to send mail as linode.com. We checked the selectors it uses by default (google, google2048) and found no key. Google Workspace lets you choose your own selector name, so this may simply mean yours is custom. If signing genuinely is not enabled, mail through this service will fail DMARC once forwarded.
Confirm DKIM is switched on in Google Workspace, then add your selector here so every future scan can verify it directly.
RFC 6376
MediumSelector 'm1' uses a 1024-bit RSA key›
1024-bit is the RFC 8301 floor, not a good target. 2048-bit is the current recommendation and is universally supported.
Rotate to 2048-bit at your next key rotation.
RFC 8301
LowNo MTA-STS policy›
Without MTA-STS, mail to your domain can be downgraded to plaintext by an active network attacker, because SMTP's STARTTLS is opportunistic by default.
Publish a TXT record at _mta-sts.linode.com and a policy file at https://mta-sts.linode.com/.well-known/mta-sts.txt.
RFC 8461
LowNo TLS-RPT record›
Sending servers have no address to report TLS failures on mail to your domain, so transport problems stay invisible to you until someone complains.
Publish 'v=TLSRPTv1; rua=mailto:<address>' at _smtp._tls.linode.com.
RFC 8460
LowNo CAA record›
Any certificate authority in the world may issue a certificate for this domain. A mis-issued certificate can be used to intercept mail on the wire and to impersonate your domain over HTTPS.
Publish a CAA record naming your certificate authority, for example: 0 issue "letsencrypt.org"
RFC 8659
InfoEligible for BIMI›
Your DMARC policy is already enforcing, which is the hard prerequisite for BIMI. Publishing a logo is now largely a branding exercise.
Publish an SVG Tiny PS logo plus a VMC, then add a default._bimi record.
InfoZone is not signed with DNSSEC›
This is the common case and not a misconfiguration -- most working mail domains are unsigned. It is worth knowing because your authentication records are only as trustworthy as the DNS answers carrying them, and because DNSSEC is the prerequisite for DANE.
If your DNS provider supports one-click DNSSEC, enabling it is low risk. If it does not, this is not worth changing providers over.
RFC 4033
Show 8 passing checks
PassAggregate reporting is configured›
Aggregate reports are requested at: [email protected].
PassExternal report destination dmarc.report-uri.com is correctly authorised›
Authorised by linode.com._report._dmarc.dmarc.report-uri.com
PassDMARC policy is p=reject›
Mail failing authentication is rejected outright. This is the correct end state.
PassSPF lookup count is healthy (5/10)›
Worst-case evaluation stays within the limit with headroom to spare.
PassSPF ends in '-all' (hard fail)›
Unauthorised hosts are explicitly rejected. This is the correct end state.
PassAdobe Marketo's DKIM key is published at m1._domainkey›
Detected via SPF include:mktomail.com. A valid public key for this service is published at m1._domainkey.linode.com.
Pass2 DKIM key(s) published›
Found at: k1, m1.
PassSelector 'k1' uses a 2048-bit RSA key›
Key length meets current guidance.
Transport and zone
Where your mail lands, and whether the DNS carrying your records can be trusted.
This is the configuration. It is not the whole picture.
A DNS scan cannot tell you whether linode.com’s mail actually aligns, because alignment is decided per message at the receiver. Collect DMARC aggregate reports to see every source sending as this domain.