B75/100

microsoftonline.com

Name: microsoftonline.com email authentication report
Creator: MailAuthWatch
License: https://creativecommons.org/publicdomain/zero/1.0/

1 fix stands between this domain and a clean A. 1 item below, ordered by how much inbox it is costing you. Measured 7 min ago from public DNS in 105 ms.

SPF PASSDKIM NOT FOUNDDMARC REJECTMX OK

Monitor this domain Re-run check

Fix these, in this order, or hand the list to your agent

ranked by impact

No DKIM key found under 79 common selectors.

Either DKIM signing is off, or it uses a selector we did not probe. Without DKIM, forwarded mail and anything that breaks SPF fails DMARC.

Do this: in Microsoft 365 Defender go to Email & collaboration → Policies → DKIM, publish the two CNAME records (selector1 and selector2) and enable signing.

Records found

SPF · TXT

v=spf1 ip4:216.32.180.228 include:spfa.microsoftonline.com include:spf-exacttarget.microsoftonline.com include:spf-msods.microsoftonline.com include:spf-mfa.microsoftonline.com include:_spf-ssg-a.microsoft.com -all

DMARC · _dmarc.microsoftonline.com

v=DMARC1; p=reject; pct=100; rua=mailto:rua@dmarc.microsoft; ruf=mailto:ruf@dmarc.microsoft; fo=1

DKIM · 0 of 79 selectors

none under common selectors

MX · Microsoft 365

10 messaging-microsoft-com.mail.protection.outlook.com

Fix this with your AI agent

AGENT-READY

A prompt built only from what was measured: the records as published, 1 task in order, exact record values and Azure DNS commands, guardrails, and how to verify. Paste it into Claude, Cursor, Copilot or ChatGPT.

# Fix email authentication for microsoftonline.com

You are working on the DNS and mail configuration for microsoftonline.com.
Measured by MailAuthWatch on 17 Oct 2026 from public DNS. Grade B (75/100).
Report: https://www.mailauthwatch.com/check/microsoftonline.com

## What is published right now (do not assume anything else)
- SPF (TXT microsoftonline.com): v=spf1 ip4:216.32.180.228 include:spfa.microsoftonline.com include:spf-exacttarget.microsoftonline.com include:spf-msods.microsoftonline.com include:spf-mfa.microsoftonline.com include:_spf-ssg-a.microsoft.com -all   — valid, 6 of 10 lookups
- DMARC (TXT _dmarc.microsoftonline.com): v=DMARC1; p=reject; pct=100; rua=mailto:rua@dmarc.microsoft; ruf=mailto:ruf@dmarc.microsoft; fo=1
- DKIM: no key found under 79 common selectors
- MX: messaging-microsoft-com.mail.protection.outlook.com  → Microsoft 365
- Nameservers: ns1-38.azure-dns.com, ns2-38.azure-dns.net …  → records are managed in Azure DNS

## Tasks, in order of impact
…

# Fix email authentication for microsoftonline.com

You are working on the DNS and mail configuration for microsoftonline.com.
Measured by MailAuthWatch on 17 Oct 2026 from public DNS. Grade B (75/100).
Report: https://www.mailauthwatch.com/check/microsoftonline.com

## What is published right now (do not assume anything else)
- SPF (TXT microsoftonline.com): v=spf1 ip4:216.32.180.228 include:spfa.microsoftonline.com include:spf-exacttarget.microsoftonline.com include:spf-msods.microsoftonline.com include:spf-mfa.microsoftonline.com include:_spf-ssg-a.microsoft.com -all   — valid, 6 of 10 lookups
- DMARC (TXT _dmarc.microsoftonline.com): v=DMARC1; p=reject; pct=100; rua=mailto:rua@dmarc.microsoft; ruf=mailto:ruf@dmarc.microsoft; fo=1
- DKIM: no key found under 79 common selectors
- MX: messaging-microsoft-com.mail.protection.outlook.com  → Microsoft 365
- Nameservers: ns1-38.azure-dns.com, ns2-38.azure-dns.net …  → records are managed in Azure DNS

## Tasks, in order of impact
### 1. No DKIM key found under 79 common selectors.
Why: Either DKIM signing is off, or it uses a selector we did not probe. Without DKIM, forwarded mail and anything that breaks SPF fails DMARC.
Add CNAME record:
  selector1._domainkey.microsoftonline.com  CNAME  selector1-microsoftonline-com._domainkey.<tenant>.onmicrosoft.com   (value comes from the provider step below)
Add CNAME record:
  selector2._domainkey.microsoftonline.com  CNAME  selector2-microsoftonline-com._domainkey.<tenant>.onmicrosoft.com   (value comes from the provider step below)
Microsoft 365 Defender → Email & collaboration → Policies & rules → Threat policies → DKIM → select the domain → Create DKIM keys.
Publish the two CNAME records it shows, then return and turn signing on.
Where: Azure portal → DNS zones → the zone → Record sets.

## Rules
- Publish exactly one SPF record; never add a second v=spf1 TXT.
- Do not remove any include: or ip4: you cannot account for; mail may depend on it.
- Do not set DMARC to p=reject in one step; stage through p=none → quarantine → reject.
- Show the planned DNS changes as a diff (record, old value, new value) before applying them.
- If you cannot access Azure DNS or Microsoft 365, stop and say exactly what access you need.

## Verify
  dig +short CNAME selector1._domainkey.microsoftonline.com
  dig +short CNAME selector2._domainkey.microsoftonline.com
  dig +short TXT microsoftonline.com
  dig +short TXT _dmarc.microsoftonline.com
Then open https://www.mailauthwatch.com/check/microsoftonline.com?fresh=1 and confirm:
  DKIM found. Target grade: A.

## Report back
List each record you changed (name, type, old value, new value), what you verified, and anything you could not do.

Open in Claude Open in ChatGPT fix.md

Your agent, your DNS, your review. MailAuthWatch never changes records; it writes the plan and re-checks the result.

Grade history

Free checks keep nothing. Monitoring records every daily measurement and alerts you on change.

History goes back as far as your subscription.

SPF OK

v=spf1 ip4:216.32.180.228 include:spfa.microsoftonline.com include:spf-exacttarget.microsoftonline.com include:spf-msods.microsoftonline.com include:spf-mfa.microsoftonline.com include:_spf-ssg-a.microsoft.com -all

DNS lookups: 6 of 10 allowed
Final mechanism: -all

OK No problems detected.

Include tree

6 / 10

microsoftonline.com0

├─ include:_spf-ssg-a.microsoft.com+2

│ └─ spf.protection.outlook.com

├─ include:spfa.microsoftonline.com+1

├─ include:spf-exacttarget.microsoftonline.com+1

├─ include:spf-msods.microsoftonline.com+1

└─ include:spf-mfa.microsoftonline.com+1

DKIM Not found

DKIM selectors cannot be listed from DNS, so 79 selectors used by common providers were probed. "Not found" means none of those selectors exist; the domain may still sign with a custom selector.

WarningNo DKIM key found under 79 common selectors. If you know your selector, add it to the check; if you have no DKIM at all, enable it at your mail provider.

DMARC OK

v=DMARC1; p=reject; pct=100; rua=mailto:rua@dmarc.microsoft; ruf=mailto:ruf@dmarc.microsoft; fo=1

Policy: p=reject
Applies to: 100% of failing mail
Aggregate reports: mailto:rua@dmarc.microsoft

OK No problems detected.

Mail exchange and extras

OK No problems detected.

MTA-STS: Not published optional: enforces TLS for inbound mail
TLS-RPT: Not published
BIMI: Not published optional: brand logo in inboxes, requires p=quarantine or reject

How the grade is calculated

Score 75/100. SPF present and valid. SPF ends with -all. DMARC present and valid. DMARC policy is reject. DMARC aggregate reporting enabled. SPF contributes up to 35 points, DKIM up to 25, DMARC up to 40 (policy strength and reporting). Any critical issue caps the grade at C. Lookups that failed are shown as "not measured" and never counted as missing.

Check another domain:

Other recently graded domains

Public checks from the last few days. Every report is re-measured from DNS when opened.

live

DomainSPFDKIMDMARCGrade

spotify.com6 lookups2048-bitp=rejectA linkedin.com2 lookups1024-bitp=rejectA google.com1 lookupsnot foundp=rejectB live.com5 lookups2048-bitp=noneB amazon.com4 lookups1024-bitp=quarantineA github.com10 lookups2048-bitp=quarantineA gmail.com1 lookupsnot foundp=noneC salesforce.com4 lookups2048-bitp=rejectA mailauthwatch.com1 lookups1024-bitp=rejectA notion.so0 lookupsnot foundp=quarantineC gandi.net2 lookupsnot foundp=noneC mailship.com1 lookupsnot foundmissingD