Cold Email A/B Testing, Test Subject Lines & Body Copy

Find the message that converts with cold email A/B testing.

Bulk Email Boxer A/B testing splits your audience across variants and shows you which version performs better.

Explore Growth A/B testing →

The problem

Most cold emailers guess at what subject lines and body copy work instead of systematically testing.

The solution

Bulk Email Boxer A/B testing splits your audience across variants and shows you which version performs better.

Everything you need, included

  • Test subject lines and body copy per step
  • Balanced exposure across active variants
  • Per-variant sent and reply rates; opens/clicks when tracking is enabled
  • Winner detection after at least 50 sends per variant at 95% confidence
  • Up to three variants per sequence step in the editor
  • The winning variant becomes active for that step

Simple, flat pricing

Starter: $40/mo · Growth: $90/mo · Scale: $350/mo

All plans include optional warmup controls, sequences, and reply handling. A/B testing is available on Growth and Scale. Seats are capped at 1, 3, or 10 by tier.

See full pricing →

How it works

Connect your email account, import contacts, build a sequence, and launch. Warmup controls remain off until you opt in. Replies from connected inboxes appear in your unified inbox.

Try Bulk Email Boxer free →