bing.com
Good, with 4 things to fix
bing.com scored 80/100 (grade B). The main issues are no DKIM key found for the common selectors and external DMARC report address is not authorized, plus 4 more. Detected senders: Microsoft 365.
Checked 2026-10-04 02:02 UTC · fresh check
Diagnosis notes
- Warning: DNS lookup budget exhausted
This diagnosis stopped sending DNS queries after 150 queries. Checks that needed more lookups report their remaining results as unknown; the domain's records may be unusually large or slow to answer.
All checks
MXCan servers find your inbox?Only one MX hostInfo
- Info: Only one MX host
All mail for bing.com goes to bing-com.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?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 bing.com 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 bing.com.
- Warning: Some DKIM lookups failed
17 of 47 selector lookups under bing.com returned TIMEOUT, so whether those selectors hold a key is unknown. Try again later; if it persists, check the domain's nameservers.
DMARCWhat happens to fakes?External DMARC report address is not authorizedNeeds attention
- Warning: External DMARC report address is not authorized
Reports go to microsoft.com, which is outside bing.com. RFC 7489 requires that domain to publish a valid v=DMARC1 TXT record at bing.com._report._dmarc.microsoft.com; without it receivers will not send you aggregate reports. Your report provider normally publishes this for you.
AlignmentDoes it match your From?No issues foundPass
Nothing to report.
BIMICan inboxes show your logo?Could not look up the BIMI recordNeeds attention
- Warning: Could not look up the BIMI record
The TXT query for default._bimi.bing.com returned TIMEOUT, so BIMI status is unknown. Try again later.
MTA-STSIs mail to you encrypted?Could not look up the MTA-STS recordNeeds attention
- Warning: Could not look up the MTA-STS record
The TXT query for _mta-sts.bing.com returned TIMEOUT, so MTA-STS status is unknown. Try again later.
TLS-RPTWill you hear about failures?No TLS-RPT recordInfo
- Info: No TLS-RPT record
No TLS reporting record at _smtp._tls.bing.com. TLS-RPT (RFC 8460) tells senders where to send daily reports about failed encrypted deliveries to you.
How to fix this
How to fix it
Enable DKIM for Microsoft 365instruction
Microsoft 365 generates the DKIM key for each account, so the exact record must come from Microsoft 365. Without DKIM, mail it sends for bing.com cannot pass DMARC through DKIM.
Applies to: selector1._domainkey.bing.com
- In Microsoft 365, enable DKIM signing for bing.com: tenant-specific: copy Selector1CNAME/Selector2CNAME from Microsoft 365 Defender > Email authentication > DKIM. Publish exactly the record Microsoft 365 shows (TXT or CNAME) at the host name it gives, then turn signing on. Instructions: https://learn.microsoft.com/microsoft-365/security/office-365-security/email-authentication-dkim-configure
Enable DKIM for Microsoft 365instruction
Microsoft 365 generates the DKIM key for each account, so the exact record must come from Microsoft 365. Without DKIM, mail it sends for bing.com cannot pass DMARC through DKIM.
Applies to: selector2._domainkey.bing.com
- In Microsoft 365, enable DKIM signing for bing.com: tenant-specific: copy Selector1CNAME/Selector2CNAME from Microsoft 365 Defender > Email authentication > DKIM. Publish exactly the record Microsoft 365 shows (TXT or CNAME) at the host name it gives, then turn signing on. Instructions: https://learn.microsoft.com/microsoft-365/security/office-365-security/email-authentication-dkim-configure
Set up a TLS report addressinstruction
Sending servers will report TLS failures when delivering to bing.com, 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.bing.com
- Pick an address that will receive TLS reports: a mailbox you read (for example tls-reports@bing.com, created first) or a TLS reporting service. 2. Publish a TXT record at _smtp._tls.bing.com with the value v=TLSRPTv1; rua=mailto:<that address>.