Email Message Error Codes
When sending emails through the maze of billions of computers world wide, you ofen come accross strange error
messages when using your favorite email client. Back in the early days of computing where only the technical
savy would have access to a computer.
While times have changed and demands for software reach toward the sky, there is only a fraction of programmers
and project managers to work on these projects to redesign it to fit our needs. Rather then send a detailed letter
that is easily understandable, most software meerly outputs a crude email error code such as 550 that leaves users
guessing.
Email server Error Codes follow a strict structure. Mail servers reply to requests from users program such as Outlook Express,
Thunderbird, Eudora, etc. This return code consists of three numbers. First digit tells whether the server accepted the
command and if it could handle it. There are five possible values:
- Accepted the command, but no action has been taken yet. A confirmation message is required.
- The mail servers task completed successfully without errors.
- Request understood, but requires further information to complete the task.
- The mail server has encountered a temporary failure. If the command is repeated without any change, it might be completed. Try again, it may help!
- Mail server has encountered a "fatal error" (serious error that prevents more work). Your requests can't be processed.
The second digit tells more describes the problem more. There are six possible values for the second digit:
- Syntax error
- Information reply (for example to HELP request)
- This digit refers to the status of connection
- Not Used
- Not Used
- This digit refers to the status of the mail server
The third digit tells even more then second again. Combination of these three digits gives us detailed list of ESMTP server
response codes, as layed down in RFC 821 and later revision.
| 211 |
System status or system help reply |
| 214 |
Help message (non-standard command help message is usually issued here too if avalible) |
| 220 |
Service ready/avalible for use |
| 221 |
Service closing transmission channel |
| 250 |
Requested mail action done/complete |
| 251 |
User/email address not on this server; will try to forward to the right user/email address if possible |
| 354 |
Start mail input; end with ".". The Mail message is fed in multiple lines using "." to signal you are done sending a message.
|
| 421 |
Service not available, closing transmission channel (This can be a reply to any command if the server is shutting down)
|
| 450 |
Requested mail action not taken: mailbox unavailable/locked/etc. |
| 451 |
Requested action aborted: the mail server has a processing error |
| 452 |
Requested action not taken: insufficient system storage (over quota) |
| 500 |
Syntax error: too long of a command, command unrecognized, command is not RFC compliant |
| 501 |
Syntax error: for the command issued, the options/parameters/arguments are wrong |
| 502 |
Command not implemented |
| 503 |
Bad sequence of commands (using the wrong protocal/language/etc.) |
| 504 |
Command parameter/option/argument not implemented |
| 550 |
Requested action not taken: mailbox unavailable (access to mailbox denied or mailbox not avalible) |
| 551 |
User/email address is not on this server; please try again later |
| 552 |
Requested mail action aborted: exceeded storage allocation (users email box is full and has no room) |
| 553 |
Requested action not taken: mailbox name not allowed (ie. you need to specifiy a different name for a mailbox) |
| 554 |
Could not complete the command since the connection was lost or corrupt temporarly |
References
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