Gmail and Yahoo bulk sender rules

Since 2024, Gmail and Yahoo enforce requirements for anyone sending in volume (more than about 5,000 messages a day to their users, counted across your domain). Everyone benefits from following them, whatever your volume.

Requirement	What it means	In SpacePost
SPF and DKIM	Authenticate every message	Done when your domain is verified (3 DKIM CNAMEs and the send records)
DMARC	A published policy for your From domain, aligned with SPF or DKIM	Add the recommended _dmarc TXT record (DMARC)
One-click unsubscribe	Marketing and subscribed mail needs List-Unsubscribe and List-Unsubscribe-Post headers	Added automatically to broadcasts; add them yourself to other bulk mail via headers
Honor unsubscribes quickly	Within 2 days	Instant for broadcasts
Low spam rate	Keep user-reported spam below 0.1% and never reach 0.3%	Monitor with Gmail Postmaster Tools; SpacePost pauses at 0.2%
Valid DNS	Forward and reverse DNS for sending servers	Handled by Amazon SES
TLS	Encrypted connections	Handled by SES
Message format	Valid RFC 5322 messages, From domain that matches your authentication	Handled by SpacePost; use a From address on your verified domain

Note

Transactional mail (password resets, receipts) is exempt from the unsubscribe requirement, but the authentication and spam-rate rules still apply.

Set up Postmaster Tools

1. Go to postmaster.google.com and add your sending domain.
2. Verify it with a DNS TXT record at your DNS provider.
3. Check Spam rate, Domain reputation, Authentication and Delivery errors regularly.

Yahoo’s equivalent is its Sender Hub and complaint feedback loop; SpacePost receives complaint feedback via SES and turns it into email.complained events.