Key facts
- Since February 2024, Gmail and Yahoo require bulk senders to set up SPF, DKIM and DMARC, keep spam rates low and offer one-click unsubscribe.
- Google wants a spam rate under 0.1 percent, never 0.3 percent or more.
- Outlook.com added authentication rules for high-volume senders in May 2025.
- Google applies its strictest rules to senders of more than 5,000 messages a day to Gmail accounts.
Who counts as a bulk sender?
Google applies its strictest rules to senders of more than 5,000 messages a day to Gmail accounts. Source: Google
What do the rules ask for?
The rules ask for three things: authentication, a low spam rate and easy unsubscribing.
- SPF and DKIM on the sending domain, and a DMARC record.
- A spam rate under 0.1 percent, and never 0.3 percent or more, in Google Postmaster Tools. Source: Google
- One-click unsubscribe on marketing mail. Yahoo asks senders to honour unsubscribes within 2 days. Source: Yahoo
How does Buzz Send keep inside them?
Mailboxes start at 5 a day and never exceed 20. A mailbox pauses after a spam complaint or at a 5 percent bounce rate, and opt-outs, complaints and bounces are suppressed for good.
How to stay inside the rules
- Authenticate every domain
SPF, DKIM and DMARC.
- Keep volume low per mailbox
Spread sends across mailboxes.
- Email relevant people only
Complaints come from people who never should have been on the list.
- Honour every opt-out
And never email that person again.
When does Buzzlist fit, and when does it not?
It fits when
- You want the limits enforced by the tool.
It does not fit when
- You want to send thousands a day from one address.
Questions people ask next
Do the rules ban cold email?
No. They set standards for authentication, complaints and opt-outs.
Where do I see my complaint rate?
Google Postmaster Tools shows it for domains with enough Gmail volume. Source: Google
Do the rules apply to Outlook?
Yes, for high-volume senders. Since May 5, 2025, Outlook.com requires SPF, DKIM and DMARC from domains that send over 5,000 emails a day. Source: Outlook.com
Is this the same as CAN-SPAM?
No. CAN-SPAM is US law. Source: FTC These are the mailbox providers' own rules.
Sources
- Google Workspace Admin Help: Email sender guidelines
- Yahoo Sender Hub: Sender best practices
- Outlook.com Postmaster: high-volume sender requirements
- Gmail Help: Postmaster Tools dashboards
- FTC: CAN-SPAM Act compliance guide for business
Checked October 9, 2026. Rules change, so read the source before you rely on it. This is general information, not legal advice.