Metrics
What is Delivery Rate?
The percentage of sent emails accepted by recipient mail servers rather than bounced.
Delivery rate is calculated as (emails sent minus bounces) divided by emails sent, expressed as a percentage. A critical caveat is that delivered does not mean inboxed: a message counts as delivered the moment the receiving server accepts it, even if that server then files it into spam. Delivery rate therefore measures acceptance, not inbox placement, and a near-100 percent delivery rate can coexist with terrible inbox placement.
Why it matters for cold email
In cold email, a delivery rate below roughly 95 percent usually signals list-quality or reputation problems, such as invalid addresses or a domain that is starting to get blocked. Because delivery rate hides spam-foldering, cold senders should pair it with seed-list inbox placement testing rather than treating high delivery as proof the campaign is working.
Related terms
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