You ask which platform “has better deliverability,” as if the inbox were a feature flag. Klaviyo and Amazon SES do not compete for the same job. One sends your campaigns and flows and manages a lot of the list hygiene for you. The other sends what your application tells it to send, and it will pause you if your bounce or complaint rate crosses Amazon’s lines.
Last verified: 26 September 2026, against Klaviyo’s bounce documentation, the SES enforcement FAQ, and the Klaviyo and SES pages already on this site.
Klaviyo vs Amazon SES: who holds the reputation
| Klaviyo | Amazon SES | |
|---|---|---|
| What it is | Marketing platform for campaigns and flows | Sending infrastructure and an API |
| Typical IP | Shared pools, dedicated IP optional | The IPs SES assigns to your sending, dedicated options included if you configure them |
| Hard bounces | Suppressed by Klaviyo | Counted toward SES bounce rate when they match the FAQ’s definition. The account can be reviewed or paused. |
| Complaints | In-product bands. Gmail does not feed complaints back to the ESP. | Complaint rate on domains that report to SES. Review and pause levels are on the SES FAQ. |
| Folder placement | Not in the deliverability hub | Not in SES events |
| Where the long page lives | Klaviyo deliverability | SES deliverability |
This table is the operational difference. It is not a score.
The published numbers differ too. Klaviyo’s help center recommends keeping your spam complaint rate below 0.08%, with under 0.01% as the ideal. SES puts your account under review at a 0.1% complaint rate and may pause sending at 0.5%; for hard bounces, review starts at 5% and a pause can come at 10%, with under 2% recommended. Those are each platform’s own lines, not Gmail’s, and SES publishes no turnaround time for a review. A 0.11% complaint rate on SES means a review, not an automatic pause. SendGrid vs SES already exists for the infrastructure comparison. Do not read that page as a Klaviyo result.
What you still have to watch on either platform
Gmail’s spam rate is in Postmaster, under 0.10% to stay comfortable and 0.30% to avoid. Yahoo’s complaint rate is in Sender Hub, under 0.30% for bulk senders. Outlook’s 550 5.7.515 is in the bounce log. Those three do not move into Klaviyo’s tile or SES’s reputation dashboard just because you picked a vendor.
Seed placement at Gmail, Yahoo, AOL and Outlook is how you see the folder. Monitoring across providers is the map. It applies to both products.
If marketing stays in Klaviyo and receipts go through SES, authenticate both, and do not assume the Klaviyo domain setup covers the SES identity. SPF’s 10-lookup limit is the usual tax on running both. Unknown DMARC sources is what the SES IPs look like in a report if nobody added them on purpose. Order confirmations in spam is what customers see when the streams share a bad reputation or the receipt path is unaligned.
How to choose
Choose Klaviyo when the work is campaigns, flows, and a list the marketing team operates, and you accept shared-pool reputation unless you move to a dedicated IP and warm it. The Klaviyo warmup page is that process. Klaviyo mail in spam is the troubleshooting page. Neither one claims Klaviyo outruns SES at Gmail.
Choose SES when engineers will own identities, configuration sets, suppression, and the application. You also own the enforcement risk in the SES FAQ: bounce and complaint rates that can pause sending. There is no inbox placement number inside that FAQ.
Choose both when the streams are different products. Write down which domain each one uses before the first receipt and the first campaign share a From address by accident. Sending architecture is that drawing. Migration is the cutover if you are leaving one of them, not a reason to run both without a plan.
InboxEagle
Check your complaint rate against both platforms' lines
Enter sends and complaints to see where you sit against Klaviyo's 0.08% recommendation, the SES 0.1% review level, and Gmail's 0.10% guideline.
Sources
- Klaviyo deliverability, InboxEagle. What Klaviyo’s own deliverability view does and does not show. The hub limitation is documented in the Klaviyo deliverability hub guide.
- Understanding bounced emails, Klaviyo. Hard-bounce suppression.
- SES enforcement FAQ, AWS. Bounce and complaint review and pause levels.
- Email deliverability FAQs, Klaviyo. Gmail complaint data is not returned to the ESP.