Delivery rate
The share of sent messages that receiving servers accepted, counting a message as delivered even when the provider then files it in the spam folder.
What it means
Delivery rate comes from SMTP results: messages the receiving server accepted (a 2xx reply) divided by messages sent. RFC 6449 states the rule behind it: once the MTA acting for the recipient accepts a message, it is considered delivered, whatever filtering happens after that point.
That is why a high delivery rate says little about the inbox. A list with almost no bounces can still be read by nobody if most of it lands in spam. Delivery rate is good at exposing list problems (hard bounces from addresses that do not exist) and blocks (5xx rejections); placement needs other evidence, such as provider dashboards or a seed test.
Platforms differ on what they count as sent, so check how your tool computes the rate before comparing figures from two of them.
Related terms
On this site
Sources
What this definition rests on. The wording is ours; the facts are theirs.
All 432 terms in the glossaryThe wiki: blocklists and bounce codes