SMTP and ESMPT Error Codes
SMTP Error Codes
Here is a list of the standard SMTP error codes you will find in most email bounces.
200 Codes
- 211 – System status / system help reply
- 214 – Help message
- 220 – Domain service ready
- 221 – Domain service closing transmission channel
- 250 – Requested mail action completed and OK
- 251 – Not Local User, forward email to forward path
- 252 – Cannot Verify user, will attempt delivery later
- 253 – Pending messages for node started