Short answer: Gmail and Yahoo filter mail from senders who don’t authenticate their domain, get too many spam reports or skip the basics. Since February 2024, anyone mailing Gmail users must sign mail with SPF or DKIM, send from a server whose DNS resolves both ways, and stay under a 0.3% spam rate. Big senders need both SPF and DKIM, plus DMARC and one-click unsubscribe.
Gmail’s rules, by volume
| Gmail requirement | Every sender | 5,000+ a day to Gmail |
|---|---|---|
| SPF and DKIM | SPF or DKIM | Both |
| DMARC | Recommended | Required, even with a none policy |
| From address aligned | Not listed | With the SPF or the DKIM domain |
| DNS that resolves both ways (PTR) | Required | Required |
| TLS connection | Required | Required |
| Spam rate | Below 0.3% | Below 0.3% |
| One-click unsubscribe | Not listed | Required in marketing and subscribed mail |
The stricter column starts once you mail Gmail accounts 5,000 times or more in a day. Below that line, Google still advises all three records.
Gmail Help, “Email sender guidelines”, as of November 2, 2026.
Yahoo’s rules are close
Yahoo’s baseline for all senders is SPF or DKIM, spam under 0.3% and DNS that resolves both ways. Its bulk senders need both SPF and DKIM, and a DMARC policy of at least p=none that passes.
Those bulk senders must also offer one-click unsubscribe plus a link people can see, and process each opt-out within 2 days.
From Yahoo Sender Hub, “Sender Best Practices”.
Other reasons mail lands in spam
Gmail says to send email only to people who want it, since they are less likely to report it as spam.
Yahoo adds three habits: send only to people who asked, keep the frequency they signed up for, and never buy lists or pre-check the opt-in box.
How to get your emails out of spam
- Sign your mail with SPF and DKIM and publish DMARC; the record formats are in our SPF, DKIM and DMARC guide.
- Ask your email provider whether its sending server’s name and address point to each other (PTR).
- Confirm your email service sends over a TLS connection.
- If you send 5,000 or more a day, align the domain in your From address with your SPF or DKIM domain.
- Put a visible unsubscribe link in marketing emails, and add one-click unsubscribe when you send in bulk.
- Send only to people who asked for your emails, as often as they signed up for.
- Watch your spam rate in Google Postmaster Tools and keep it under 0.3%.
The federal rules for marketing email are in our guide to the CAN-SPAM Act.
From Gmail Help and Yahoo Sender Hub.
Our own email, checked
We opened the original of an automatic alert our own system sent from info [at] feedback-studios.com on the morning of November 2, 2026. The receiving mail server, our mailbox host, recorded SPF pass, DKIM pass with our domain and DMARC pass.
Gmail’s summary of the same message showed DKIM PASS with domain feedback-studios.com. Our DMARC policy is reject, stricter than the none that Gmail and Yahoo accept from bulk senders.
The server that sent it has a reverse DNS name, mout.perfora.net, that points back to its address. The delivery records show encrypted ESMTPS connections.
Before your next send
- SPF and DKIM pass for your domain.
- A DMARC record is published.
- The sending server’s DNS resolves both ways.
- Mail goes out over TLS.
- Fewer than 3 spam reports per 1,000 emails.
- Marketing mail has an unsubscribe link, one-click in bulk.
RememberAuthenticate your domain, mail only people who asked, make unsubscribing easy, and keep spam reports under 0.3%.
Our email and SMS service can set up the domain and run your email marketing for you.
Quick answers about emails going to spam
Why are my emails going to spam?
Usually because the domain isn’t authenticated, too many people mark the mail as spam, or it goes to people who didn’t ask for it. Both Gmail and Yahoo want SPF or DKIM on the mail and fewer than 3 spam reports per 1,000 emails.
Do Gmail’s sender rules apply to a small business?
Yes. The baseline covers anyone who mails Gmail accounts, whatever the size: SPF or DKIM, DNS that resolves both ways, TLS and spam under 0.3%. The stricter list starts at 5,000 daily messages.
Is there a limit on the spam rate?
Yes. Gmail asks senders to keep the spam rate reported in Postmaster Tools below 0.3%, and Yahoo asks for the same. Yahoo counts it on mail delivered to the inbox.
Do I need DMARC?
From 5,000 daily messages to Gmail accounts, yes, though a none policy is enough. Yahoo has the same rule for its bulk senders, and below that line Google still advises it.
How fast do I have to honor an unsubscribe?
Within 2 days, for Yahoo’s bulk senders. Gmail’s rule for big senders is about the mechanism: one-click unsubscribe in marketing and subscribed messages, plus a link people can see.
Sources
Sources as of November 2, 2026: Email sender guidelines in Gmail Help, and Sender Best Practices in Yahoo Sender Hub. Our own case: the original of an email our system sent on November 2, 2026, and our domain’s DNS records.