Non-compliant mail is rejected or filtered at the two largest consumer mailbox providers. Enforcement has tightened each year since.
How to implement bulk sender requirements#
- Publish SPF and DKIM, and a DMARC record at minimum p=none with aligned From domain.
- Add List-Unsubscribe headers and honor requests within two days.
- Use a valid forward and reverse DNS (PTR) for sending IPs.
- Monitor spam rate in Postmaster Tools and keep it under 0.1%.
- Send from a subdomain with its own reputation for marketing.
How to verify it worked#
Send a test message to seed mailboxes at Gmail, Outlook, and Yahoo, then inspect the Authentication-Results and delivery headers. Repeat after any DNS or sending-platform change.
Common mistakes#
- Thinking the rules only apply above 5,000; Gmail applies most of them to all senders.
- Using a gmail.com From address for bulk mail, which fails DMARC alignment.
Frequently asked questions#
What happens if I do not comply with Gmail bulk sender rules?
Temporary failures (4xx) escalating to rejections, and reduced inbox placement. Gmail announced enforcement in stages through 2024 and beyond.