Email · Website glossary

SMTP status code

Quick answer · What is SMTP status code?

A server reply code describing the result of a step in an SMTP exchange.

IN PRACTICE

SMTP status code: an example

A temporary 4xx response can lead to a later retry, while a 5xx response indicates a permanent negative completion for that request.

KEEP IN MIND

The accompanying enhanced code and text provide context; the first digit alone is not a complete diagnosis.

Put the idea to work

Frequently asked questions

What is a practical example of SMTP status code?

A temporary 4xx response can lead to a later retry, while a 5xx response indicates a permanent negative completion for that request.

Is the first digit of an SMTP status code a complete diagnosis?

The accompanying enhanced code and text provide context; the first digit alone is not a complete diagnosis.

Which concepts should I read alongside SMTP status code?

Email bounce: A delivery failure notification generated when a message cannot be delivered as expected.
SMTP: Simple Mail Transfer Protocol is used to submit and transfer email between systems.