Let optimization run your A/B tests
Write as many variants as you want for any step in the sequence. The optimization engine shifts sending volume toward whatever's winning and quietly pauses what isn't. You control the guardrails: minimum sends per variant, how many days it waits before acting, and the threshold that triggers an auto-pause.
A/B Testing
Outreach
Write your variants
Draft multiple versions, A, B, C, and beyond, for any step in your sequence. Test subject lines, body copy, or both at once.
- As many variants as a step needs
- Volume shifts on its own
- Underperformers get benched
- Each step tests independently
A look inside the Sendbox dashboard, where A/B Testing lives.
Campaigns
Campaign | Status | Leads | Sent | Opened | Replied | Positive | Bounced | |
|---|---|---|---|---|---|---|---|---|
Fintech Ops Leaders | Active | 3,600 | 2,510 | 1,620(64.5%) | 189(7.5%) | 79(41.8%) | 41(1.6%) | |
Seed Stage Founders – NYC | Active | 1,500 | 980 | 615(62.8%) | 112(11.4%) | 54(48.2%) | 14(1.4%) | |
Agency Growth Partners | Paused | 4,800 | 3,204 | 1,798(56.1%) | 176(5.5%) | 61(34.7%) | 71(2.2%) | |
Enterprise Security Buyers | Completed | 6,300 | 4,488 | 2,915(64.9%) | 402(9.0%) | 161(40.0%) | 79(1.8%) | |
Ops Leaders Q2 2026 | Draft | 760 | - | - | - | - | - |
The numbers choose the winner, not you
As many variants as a step needs
Create however many variants a step calls for, testing subject lines, body copy, or both in the same run.
Volume shifts on its own
Sending volume reallocates toward top performers automatically, with no manual intervention required.
Underperformers get benched
Variants that consistently lag get paused once your configured thresholds are met.
Each step tests independently
A/B tests at one step run separately from every other, optimizing step 2 has no bearing on what happens at step 4.
Step 1
Write your variants
Draft multiple versions, A, B, C, and beyond, for any step in your sequence. Test subject lines, body copy, or both at once.
Step 2
Set the optimization thresholds
Decide the minimum sends per variant before optimization can act, how many days to wait first, and the threshold that triggers an auto-pause. A minimum variant count is available too.
Step 3
Hand it off to the algorithm
From here, the system keeps shifting more volume toward whatever's converting best and automatically pauses variants that fall below your thresholds.
Where it fits
Dialing in subject lines
Run several subject lines on your first send. Once optimization spots a leader, that variant starts claiming most of the remaining volume.
Testing every step independently
Give each step its own set of variants running on its own clock. Optimize the entire sequence, not just the opener.
Iterating on the message itself
Try different value props, calls to action, or email lengths, and let performance data settle the argument instead of a gut call.
Optimization built on rules, not gut feel
Sendbox calls the winner, you just set the rules
A lot of tools let you spin up variants, then leave you to eyeball the results and pick a winner yourself. Sendbox's optimization engine shifts volume toward whatever's converting and quietly pauses the underperformers. Set your thresholds once and let the system run the split test.
- Beats Instantly
- Beats Lemlist
Optimization you can see into
You decide when the engine acts.
- Set the minimum sends per variant, the minimum number of days before anything gets paused, and the auto-pause threshold.
- Raise the minimum variant count if you'd rather keep more options alive longer.
- The math runs on your terms.
As many as you need, A, B, C, and beyond, with no strict ceiling.
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