Glossary
Delivery rate
Also called accepted rate.
Last reviewed 18 September 2026
What is a delivery rate?
A delivery rate is the share of a send that the receiving mail server accepted instead of bouncing, and it says nothing at all about whether any of it reached an inbox.
It is the number a sending dashboard can actually see, which is why it is the number sending dashboards show. Ninety-nine per cent delivered is entirely compatible with every message sitting in a spam folder, so a sender can look healthy on their own reports for months while their mail quietly stops arriving anywhere a person looks.
The useful thing to do with it is watch it move rather than admire it. A drop means bounces, and a jump in bounces means either a list nobody confirmed or a suppression list that is not being applied before the send.
See also
- Deliverability
Deliverability is the share of the mail you send that reaches the inbox of the person you addressed it to, as distinct from delivery, which is only the share the receiving server accepted rather than bounced.
- Hard bounce
A hard bounce is a permanent refusal of a message by the receiving server, carried in a 5xx SMTP response, because the mailbox does not exist, the domain does not exist, or the address has been disabled.
- Soft bounce
A soft bounce is a temporary refusal of a message by the receiving server, carried in a 4xx SMTP response, because the mailbox is full, the server is greylisting you, or you are being rate-limited.
Read next
This term is covered properly in Email deliverability for small senders: authentication and reputation, which is a longer piece on the subject.
Every other term is on the glossary index , the longer writing is in the guides, and what this site itself does is on the home page.
Thinking of writing one of these?
5dayemail hosts a five-to-ten day email course: you write it once, and everyone who joins your list gets one email a day, in order, starting from the day they confirm.
Accounts are opened a few at a time rather than by signing up. Leave your address and you will be written to when the next ones open.
One message, when there is room. No course emails, no newsletter, and the address is not passed on. Ask and it is deleted; what is kept, and for how long, is in the privacy policy.