Google treats a domain as a bulk sender after it sends roughly 5,000 or more messages to personal Gmail accounts in a 24-hour period. Messages from subdomains count toward the same primary-domain total, and Google says bulk-sender classification does not expire. Since February 1, 2024, these senders have had to meet the additional requirements below.
The two numbers to monitor
The volume trigger is about 5,000 messages per day to personal Gmail accounts. In Google Postmaster Tools, keep user-reported spam below 0.1% and prevent it from ever reaching 0.3% or higher. The 0.3% figure is a ceiling, not a healthy target.
Google requires SPF and DKIM, a DMARC record of at least p=none, DMARC alignment, valid forward and reverse DNS, TLS, proper message formatting, and RFC 8058 one-click unsubscribe for marketing and subscribed messages. A visible body unsubscribe link is also required, and requests must be honored within two days. Review Google’s current sender guidelines and FAQ before a high-volume launch.
Start with a sender inventory
List every platform that sends as your domain, including employee mailboxes, newsletters, CRM sequences, support tools, invoicing systems, and website forms. For each one, record who owns it, what From domain it uses, its return-path if known, and whether it sends promotional or transactional mail. This inventory prevents a change made for a marketing platform from breaking an overlooked billing or support sender.
Set up SPF correctly
SPF identifies systems allowed to send using the envelope-from domain. Publish only one SPF record for a domain; multiple records can produce a permanent error. Add vendor-approved mechanisms to the existing policy rather than pasting a second full example. Check the expanded DNS lookup count after additions, because SPF allows no more than ten. Read how to check SPF and the ten-lookup limit guide before changing a complex record.
Enable DKIM for every relevant provider
DKIM signs mail with a private key while DNS publishes the matching public key at a selector record. Enable the provider’s DKIM feature, publish the exact selector it supplies, and send a fresh test. The receiver-side header should show a DKIM pass. Do not assume the DKIM setup for employee mail also covers your ESP or CRM. Our DKIM check guide explains the evidence to look for.
Publish and maintain DMARC
DMARC evaluates whether SPF or DKIM passed with an identity aligned to the visible From domain. Start with monitoring if you have not yet inventoried all senders, then progress deliberately toward enforcement once legitimate traffic is stable. A record that simply exists is not the same as a policy that protects the brand. See DMARC policy options for a safe progression.
Make unsubscribe easy
Bulk promotional mail should include a visible unsubscribe link and support one-click unsubscribe when required. The action should work without a login, survey, or confusing sequence of steps. Separate promotional messages from password resets, receipts, and other essential transactional mail so the subscriber’s choice can be honored without disrupting account communications. See one-click unsubscribe explained.
Protect sender reputation
Authentication does not make unwanted mail welcome. Send to people who reasonably expect the message, maintain suppression lists, remove invalid addresses, and avoid abrupt volume spikes to inactive audiences. Watch complaint, bounce, and engagement patterns by sending stream. When placement falls, inspect fresh headers and recent platform changes before repeatedly changing DNS.
Build a pre-send checklist
- Confirm the audience and consent basis.
- Verify From domain, SPF, DKIM, and DMARC alignment.
- Test unsubscribe behavior and suppression handling.
- Send a small test and inspect message headers.
- Assign an owner for responses, complaints, and vendor changes.
Repeat this check after a new sender, mail migration, rebrand, or DNS move. The requirements are best treated as normal email operations rather than a one-time compliance project.
Run Beacon’s free domain check to review the public SPF, DKIM, and DMARC signals supporting your sending program.
Keep evidence for changes
Save the current DNS values, provider settings, test header, and owner whenever a sender is added. This record makes later deliverability troubleshooting faster and prevents accidental removal of an authorization that another business workflow still needs.