Land in the inbox
& boost conversions.

Send emails to Primary, not Promotions.

The Inbox Booster gets your campaigns into the primary inbox instead of the Promotions tab or spam folder — so the emails you already send actually get seen.

Book a demo
Primary
Promotions
  • {Your brand}You have an upcoming order
  • MomThis weekend
  • David HRe: Appointment reminder

Integrates with

KlaviyoAttentiveBrazeIterable& more

The results

+86%open-rate lift
+12%click-rate lift

Average across 11 customer orgs · 24.6M recipients tracked.

What is the Inbox Booster?

The Inbox Booster is an email deliverability tool that gets your emails into the primary inbox instead of the Promotions tab or spam folder. It works alongside Klaviyo and your existing ESP, optimizing how each send is read by inbox filters so your campaigns actually get seen.

No new sending platform. No migration. It's a lightweight block that rides on the emails you already send.

Standout — Grinds

Grinds

Grinds turns pouches into inbox wins. With the Inbox Booster landing their campaigns in Primary instead of Promotions, they more than tripled opens across millions of sends — reaching customers who never used to see the email at all.

+227%open lift
+26%click lift
2.89Mrecipients

How the booster works.

01

Add the block.

A lightweight Inbox Booster block goes on your existing email — no new sending platform, no migration.

02

Vary every send.

It injects dynamic, varied text so each email reads uniquely to inbox classifiers like Gmail and Yahoo, which is what drives primary placement.

03

Auto-optimize.

Every send runs as a live A/B test, boosted against control, and automatically swaps to the winning variant.

04

See the lift.

Placement and dollar impact are reported transparently, so you always know what it's earning.

Frequently asked questions

Have a question we didn't cover? Book a demo and ask.

Yes. The Inbox Booster runs alongside the ESP you already use, including Klaviyo. You keep building and sending exactly as you do today — there's no new platform to learn and nothing to migrate.

No. It's a lightweight block that rides on the emails you already send through your current infrastructure. Your sending setup doesn't change.

Every send runs as a live A/B test against your own control group. The open-rate, click-rate, and placement figures you see are validated against that control — measured on your own flows, not borrowed from someone else's benchmark.

No. The booster works within your existing sending infrastructure and optimizes how each message is read by inbox classifiers — it doesn't spoof, cloak, or manipulate reputation signals. It makes the legitimate email you already send read more like the primary-inbox mail people want.

Primary-tab placement is driven by classifiers at providers like Gmail and Yahoo, and that's where the booster focuses. Results are strongest where an inbox sorts mail into Primary and Promotions tabs.

Because every send is a live test, you start seeing placement and open-rate movement within the first few campaigns rather than waiting on a long ramp.

Go deeper in the Help Center

See it running on your own flows.

Measured against your own control. Every figure A/B-test validated. Book a demo and we'll show you the lift on your sends.

Book a demo