Can A/B testing directly measure deliverability?

A/B testing has limitations for directly measuring deliverability:

You cannot observe placement: Standard A/B tests measure recipient behavior (opens, clicks) but cannot directly measure whether emails reached the inbox versus spam folder.

Opens suggest delivery: If recipients open, the email was delivered somewhere they could find it. But non-opens could mean spam folder, inbox ignored, or delivery failure.

Confounding factors: Engagement differences between variants could result from content appeal or deliverability differences. You cannot easily separate these.

For direct deliverability testing, use seed list testing tools that place test addresses at mailbox providers and directly observe where mail lands.

A/B testing measures what happens after delivery. Use specialized tools to measure delivery itself.