Post Office Protocol version 3 (POP3) Extension Mechanism
- Last Updated
- 2013-03-13
- Note
-
The POP3 Extension Mechanism [RFC2449] updates [RFC1939] to define a mechanism to announce support for optional commands, extensions, and unconditional server behavior. Please see Section 1 of [RFC2449] for details regarding POP3 Extensions.
- Available Formats
-
XML
HTML
Plain text
Registries Included Below
POP3 Capabilities
- Registration Procedure(s)
-
Standards Track or IESG-approved Experimental RFC
- Reference
- [RFC2449]
- Available Formats
-
CSV
| CAPA Tag | CAPA Args | Added Cmds | Cmds Affected | List | Diffs | Cmd Valid | References |
|---|---|---|---|---|---|---|---|
| TOP | none | TOP | none | both | no | TRANSACTION | [RFC2449][RFC1939] |
| USER | none | USER, PASS | none | both | no | AUTHENTICATION | [RFC2449][RFC1939] |
| SASL | mech list | AUTH | none | both | no | AUTHENTICATION | [RFC2449][RFC5034] |
| RESP-CODES | none | none | none | both | no | n/a | [RFC2449] |
| LOGIN-DELAY | secs, USER | none | USER, PASS, APOP, AUTH | both | yes | n/a | [RFC2449] |
| PIPELINING | none | none | all | both | no | n/a | [RFC2449] |
| EXPIRE | days, NEVER, USER | none | none | both | yes | n/a | [RFC2449] |
| UIDL | none | UIDL | none | both | no | TRANSACTION | [RFC2449][RFC1939] |
| IMPLEMENTATION | text | none | none | TRANS, both | no | n/a | [RFC2449][RFC1939] |
| STLS | none | STLS | USER, PASS, CAPA | both | no | AUTHENTICATION | [RFC2595] |
| AUTH-RESP-CODE | none | none | none | both | no | n/a | [RFC3206] |
| UTF8 | USER | UTF8 | USER, PASS, APOP, LIST, TOP, RETR | both | no | AUTHORIZATION | [RFC6856] |
| LANG | none | LANG | all | both | no | AUTHORIZATION TRANSACTION | [RFC6856] |
POP3 Response Codes
- Registration Procedure(s)
-
RFC Specification Required
- Reference
- [RFC2449]
- Note
-
See Section 9 of [RFC2449] for details regarding Response Codes.
- Available Formats
-
CSV
| Response Code | Response Types | Commands | Reference |
|---|---|---|---|
| LOGIN-DELAY | -ERR | USER[1], PASS, APOP, AUTH | [RFC2449] |
| IN-USE | -ERR | PASS, APOP, AUTH | [RFC2449] |
| SYS/PERM | -ERR | All commands | [RFC3206] |
| SYS/TEMP | -ERR | All commands | [RFC3206] |
| AUTH | -ERR | Any authentication command including AUTH USER [2], PASS, or APOP. | [RFC3206] |
| UTF8 | -ERR | LIST, TOP, RETR | [RFC6856] |
Footnotes
| [1] |
see spec for details |
| [2] |
Returning the AUTH response code to the USER command reveals to the client that the specified user exists. It is strongly RECOMMENDED that the server not issue this response code to the USER command. |