From 1/2/2024, Google applied new requirements for bulk email senders to Gmail accounts, and Yahoo announced similar requirements in the same period. If your business sends newsletters, promotional emails or notifications to many customers, your email may be sent to spam or rejected if it doesn't comply. This article briefly explains and lists what to check.
Who the rules apply to
According to Google's guidance, senders who send more than 5,000 emails a day to Gmail accounts are "bulk senders" and must meet all the requirements below. Some basic requirements, such as SPF or DKIM authentication, apply to smaller senders too. Once you've crossed the threshold, Google continues to treat you as a bulk sender afterward. For small businesses, even if you haven't reached the threshold, following these steps still helps your email reach the inbox more reliably.
Three layers of authentication: SPF, DKIM, DMARC
| Term | What it does | Easy analogy |
|---|---|---|
| SPF | Declares which servers are allowed to send email on behalf of your domain | List of people allowed to sign letters |
| DKIM | Attaches a digital signature to the email to prove the content hasn't been altered | Tamper-proof seal |
| DMARC | Tells the receiving server what to do if SPF or DKIM doesn't match, and sends you reports | Rules for handling forged mail |
Google requires bulk senders to set up SPF and DKIM, and also to have a DMARC policy. The DMARC policy can be "none" (monitor only) to start. The domain in the "From" field must align with the SPF or DKIM domain. DKIM keys should be at least 1024 bits, with 2048 bits recommended.
One-click unsubscribe
Promotional emails and subscription messages must support one-click unsubscribe:
- Include the List-Unsubscribe and List-Unsubscribe-Post headers following the one-click standard.
- Include a clear unsubscribe link in the email body.
- Process unsubscribe requests quickly. According to the guidance documents at the time, within about two days.
Most major email marketing services already have this feature. If you send with your own software or a WordPress plugin, double-check.
Keep the spam rate low
Google requires the spam report rate in Postmaster Tools to stay below 0.30% and recommends below 0.10%. In practice:
- Only send to people who have agreed to receive.
- Use honest, non-sensational subject lines. The content should match the subject.
- Clean your list: remove addresses that haven't responded in a long time or that bounce.
- Keep your sending frequency steady and avoid suddenly sending large volumes.
Other technical requirements
Google also lists: a valid PTR record (reverse DNS), TLS for email transmission, and message formatting per the RFC 5322 standard. Don't forge the Gmail "From" header. Ask your domain administrator or email provider to check these items.
Quick checklist
- Look up your domain's SPF, DKIM and DMARC records with a free checking tool.
- Send a test email to Gmail and view "Show original" to see whether SPF, DKIM and DMARC pass.
- Register for Google Postmaster Tools to monitor your spam rate.
- Check the unsubscribe button in every email template.
- Separate transactional emails (invoices, confirmations) from promotional emails if possible.
2026 update: According to some industry analyses, from around late 2025 Gmail stepped up enforcement against non-compliant traffic. The details of the policy may change, so compare against Google's official guidance pages when configuring.
FAQ
Do small businesses that send few emails need to do this?
The full requirements apply to senders of over 5,000 emails a day to Gmail, but SPF, DKIM and DMARC authentication is good practice for every sender because it reduces the chance of landing in spam.
Is DMARC required to be set to a blocking level?
According to Google, bulk senders need DMARC but the policy can be at "none". You can start by monitoring reports and then gradually raise the protection level.
Who can check it for me?
A domain administrator or email marketing provider can usually do it. If you need help, you can contact HVSC's Technology team.
Reference sources
- Google Workspace Admin Help, Email sender guidelines — https://support.google.com/a/answer/81126
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FAQ
Do small businesses that send few emails need to do this?
The full requirements apply to senders of over 5,000 emails a day to Gmail, but SPF, DKIM and DMARC authentication is good practice for every sender because it reduces the chance of landing in spam.
Is DMARC required to be set to a blocking level?
According to Google, bulk senders need DMARC but the policy can be at "none". You can start by monitoring reports and then gradually raise the protection level.
Who can check it for me?
A domain administrator or email marketing provider can usually do it. If you need help, you can contact HVSC's Technology team.
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