Eight checks per Klaviyo account before peak volume
Since November 2025 Gmail’s enforcement includes rejecting non-compliant mail, and an account that crosses the 0.3% spam-rate line loses Google’s help until it has stayed under it for seven straight days. The checklist, with where to look.
Since November 2025, Google’s FAQ says Gmail is ramping up enforcement of its sender requirements, and mail that fails them will see disruptions “including temporary and permanent rejections”, not only spam-foldering. Above a 0.3% user-reported spam rate, Google’s delivery support and mitigations are unavailable until the rate has stayed below 0.3% for seven consecutive days. On 10,000 messages delivered to Gmail, 30 spam reports is 0.3%. In a launch month, seven clean days is a week you cannot spare.
Run the checks below per account and per sending domain in September or October, and file the result with the date. “Where” is the screen to open. “Pass” is the source’s condition where a source states one and is marked “ours” where it is not. The sources are at the end.
| Check | Where | Pass |
|---|---|---|
| 1. Sending domain is a branded domain, not a shared or free-mail one | Klaviyo’s sending domain settings | The from-address root domain matches the branded sending domain. Klaviyo says not to use a Gmail or Yahoo address as the from-address. |
| 2. SPF, DKIM and DMARC pass and align | Postmaster Tools, Compliance status; or Show original on a test sent to a Gmail address | SPF and DKIM both pass; DMARC passes and aligns with the from domain; policy at least p=none. Google requires all three from bulk senders, close to 5,000 messages a day to personal Gmail accounts, counted across the primary domain and its subdomains. |
| 3. One-click unsubscribe present | Show original on the same test | List-Unsubscribe and List-Unsubscribe-Post: List-Unsubscribe=One-Click headers in the source. Klaviyo adds them to every email; this confirms it. |
| 4. Unsubscribes take effect | Use Gmail’s unsubscribe button at the top of the test message, next to the sender name, then open the profile in Klaviyo | Profile suppressed within 48 hours, which is Google’s recommendation and inside Yahoo’s two-day requirement. If Gmail shows no button, that is a finding in itself: Google shows it only for mail that passes its eligibility checks. |
| 5. Postmaster Tools connected for the domain | postmaster.google.com | Domain verified and the Spam Rate dashboard shows daily readings. Google says dashboards may leave out data on low-volume days. If there is still no data after seven days of sending (our cutoff), record the account as unmeasured, not as passing, and keep row 8’s suppression on until readings appear. |
| 6. Spam rate, last 30 daily readings | Postmaster Tools, Spam Rate | Every daily reading below 0.10%; no reading at or above 0.30%. |
| 7. Complaint rate by send, last 30 days | Klaviyo deliverability hub | Ours: no send above twice the median complaint rate of the account’s sends in the same 30 days. |
| 8. Who receives the peak-season sends | Klaviyo segments | Ours: a suppression segment is applied to every promotional send, with its definition written on this sheet. Example definition: profiles that have received at least five emails and have not opened, clicked or ordered in 180 days. |
Rows 1 to 5 are configuration. Rows 6 to 8 are the complaint rate and the audience, and they change with every send. If any of the last 30 daily readings in Postmaster’s Spam Rate dashboard is at or above 0.10%, apply row 8’s suppression before adding November volume, and read the dashboard every morning through the peak sends, since Google says the data is typically updated within 24 hours but can take longer, and seven clean days is the cost of crossing 0.3%.
Yahoo’s bulk-sender requirements, for the same accounts: SPF and DKIM, a DMARC policy of at least p=none that passes, a working list-unsubscribe header, unsubscribes honoured within two days, valid forward and reverse DNS for sending IPs, and a spam rate below 0.3%.
Sources
- Email sender guidelines · Google
- Email sender guidelines FAQ · Google
- Sender best practices · Yahoo
- Email deliverability FAQs · Klaviyo Help Center, March 31, 2026