| 211 |
System status or system help response |
| 214 |
Help message |
| 220 |
Service ready |
| 221 |
Service closing transmission channel |
| 235 |
Authentication successful |
| 250 |
Requested mail action completed |
| 251 |
User not local; will forward |
| 252 |
Cannot verify the user; will attempt delivery |
| 354 |
Start mail input; end with <CRLF>.<CRLF> |
| 421 |
Service not available, closing transmission channel |
| 450 |
Requested action not taken - mailbox unavailable |
| 451 |
Requested action aborted: local error in processing |
| 452 |
Requested action not taken - insufficient system storage |
| 500 |
Syntax error, command unrecognized |
| 501 |
Syntax error in parameters or arguments |
| 502 |
Command not implemented |
| 503 |
Bad sequence of commands |
| 504 |
Command parameter not implemented |
| 550 |
Requested action not taken - mailbox unavailable |
| 551 |
User not local; please try <forward-path> |
| 552 |
Requested mail action aborted - exceeded storage allocation |
| 553 |
Requested action not taken - mailbox name not allowed |
| 554 |
Transaction failed |
