Email marketing · Compliance
Authenticate your domain, make unsubscribing one click, and keep complaints under 0.3%. Here is what each rule means and how to check yours.
SPF, DKIM and DMARC for bulk
One-click unsubscribe on marketing
Spam complaints under 0.3%
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Since February 2024, Gmail and Yahoo require anyone sending email to their users to meet basic standards, with stricter rules for bulk senders. Google defines a bulk sender as one that sends close to 5,000 or more messages to personal Gmail accounts in 24 hours. Bulk senders must:
Microsoft’s Outlook added similar SPF, DKIM and DMARC requirements for domains sending over 5,000 emails a day in May 2025. Meeting the Gmail and Yahoo rules covers most of Outlook’s too.
SPF or DKIM; valid forward and reverse DNS; TLS (Gmail); spam rate below 0.3%; messages formatted to email standards; no impersonating Gmail addresses in the From header.
Everything for all senders, plus SPF and DKIM both, DMARC with alignment, one-click unsubscribe with a visible body link, and unsubscribes processed within two days.
Two details catch businesses out. First, Google counts all mail from the same primary domain, including subdomains, toward the 5,000 total. Second, Google says bulk sender status does not expire. Once you are classed as a bulk sender, sending less later does not remove the label.
Marketing and subscription email must include a List-Unsubscribe header supporting one-click unsubscribe. This is what powers the “Unsubscribe” button Gmail and Yahoo show next to the sender name. Yahoo highly recommends the RFC 8058 POST method. You also need a clearly visible unsubscribe link in the email body.
Book a free 30-minute call. We look at your domain records, email platform and recent campaigns with you and tell you what we would fix first. No obligation. Pick a time.
The spam rate is the share of delivered messages that recipients mark as spam. Gmail measures it in Google Postmaster Tools; Yahoo calculates it from mail delivered to the inbox. The ceiling is 0.3%, and Google recommends staying below 0.1%.
Google says bulk senders above 0.3% are not eligible for mitigation, and become eligible again only after staying below 0.3% for seven consecutive days. To stay under the limit:
Google says unauthenticated messages may be marked as spam or rejected with a 5.7.26 error, and that from November 2025 Gmail ramped up enforcement with temporary and permanent rejections of non-compliant mail. Microsoft’s Outlook rejects high-volume mail that fails its authentication rules with a 550 5.7.515 error. In practice, non-compliance shows up as falling open rates, then bounces.
Repeat the test for every system that sends as your domain, including invoices and website form notifications. Those are often the ones that fail.
Our email marketing team sets up domain authentication, unsubscribe handling and list hygiene on MailChimp, Klaviyo and HubSpot. If you are choosing between those platforms, see Klaviyo vs Mailchimp vs HubSpot. Florida businesses can also read about email marketing in Fort Lauderdale.
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The authentication, spam-rate and DNS basics apply to all senders. The stricter bulk-sender rules apply once you send close to 5,000 or more messages a day to Gmail users, counted across your whole domain.
For the Gmail and Yahoo bulk-sender requirements, yes, as long as DMARC passes with alignment. Moving to quarantine or reject later gives stronger protection against spoofing.
Both set the limit below 0.3%. Google recommends staying below 0.1%.
No. Google says one-click unsubscribe applies to marketing and promotional messages, not transactional ones such as password resets or order confirmations.
