Bulk sender requirements from Gmail, Yahoo and Microsoft
If you send more than about 5,000 messages a day to any of them, these rules decide whether your mail is delivered. Here is each rule in plain terms, with the free tool that checks it.
1. Authenticate with SPF and DKIM
Both, not one. SPF lists the servers allowed to send for your domain; DKIM signs each message. Forwarded mail breaks SPF, so DKIM is what keeps DMARC passing. Check SPF · Check DKIM
2. Publish DMARC, at least p=none
A DMARC record at _dmarc.yourdomain with a policy. Start at p=none with a rua address so you receive reports; the providers expect you to move toward enforcement. Check DMARC · Generate a record
3. Align the From domain
The domain in the visible From header must match the SPF domain or the DKIM signing domain (relaxed alignment allows subdomains). Aggregate reports show alignment per sending source. This is what EmailSecOps monitoring measures every day.
4. Valid forward and reverse DNS
Every sending IP needs a PTR record that resolves back to the same IP. Check reverse DNS
5. Keep spam complaints under 0.3%
Measured in Google Postmaster Tools; stay under 0.1% to be safe. Blacklist listings are the early warning. Check blacklists
6. One-click unsubscribe for marketing mail
List-Unsubscribe and List-Unsubscribe-Post headers, honoured within two days. This is set in your sending platform, not in DNS.
7. Use TLS for delivery
Send over STARTTLS. To require it for mail you receive, publish MTA-STS and TLS-RPT. Check MTA-STS
Common questions
Do the rules apply if I send fewer than 5,000 a day?+
Is p=none enough?+
What if my marketing vendor sends from their domain?+
Find out in one check whether you comply.
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