Gmail & Yahoo sender requirements

Since early 2024, Gmail and Yahoo enforce a common set of rules for anyone sending meaningful volume to their users (Gmail draws its bulk-sender line at roughly 5,000 messages a day to Gmail addresses, but the rules are best practice at any volume). Mail that doesn't comply is filtered to spam or rejected outright — these are requirements, not suggestions. The good news: on Bird, each one maps to a step you've likely already taken.

Bulk senders must authenticate with SPF and DKIM, and publish a DMARC record — and the authentication must align, meaning it passes in the name of the same domain your recipients see in the From address.

On Bird: verifying your sending domain covers all of it. Publishing the DNS records from your domain's detail page gives you DKIM signing in your domain's name and a DMARC record, and the return-path CNAME provides SPF alignment — SPF is evaluated against your bounce domain, which the CNAME points at Bird's infrastructure, so it passes and aligns without you adding an SPF record at your domain's apex. Don't be surprised that Bird never asks you for an apex SPF entry; that's by design. The walkthrough is in the sending domains guide.

Marketing and promotional mail must carry a one-click unsubscribe option in the message headers (the technical standard is RFC 8058) — the "Unsubscribe" link mail clients show next to the sender name — and opt-outs must be honored within two days.

On Bird: Bird adds the required one-click List-Unsubscribe headers automatically on broadcast (marketing) sends, and recipients who use them are suppressed from future marketing mail immediately. You should still keep a visible unsubscribe link in the message body itself — the header doesn't replace it, and recipients who can't find a way out click "mark as spam" instead.

Senders must keep their spam-complaint rate below 0.3%, and ideally below 0.1%. This is the requirement that demands ongoing attention rather than one-time setup: 0.3% is roughly one complaint per 300 delivered messages, and providers filter aggressively once you cross it.

On Bird: the Metrics page in the dashboard tracks your complaint rate over time, and Bird automatically suppresses anyone who complains so they're never mailed again. Staying under the line is about list quality — sending to people who opted in and pruning the unengaged. See sender reputation monitoring for the thresholds and what to do when the rate climbs, and the email consent article for getting permission right in the first place.

Beyond these three headline rules, the providers' guidelines also expect basics Bird handles as a matter of course — valid forward and reverse DNS on sending IPs, standards-compliant message formatting — so domain verification plus a clean list is genuinely the whole job.