twisted.mail.pop3.AdvancedPOP3Client : API documentation

A POP3 client protocol.

Instances of this class provide a convenient, efficient API for retrieving and deleting messages from a POP3 server.

This API provides a pipelining interface but POP3 pipelining on the network is not yet supported.

Instance Variable	startedTLS	An indication of whether TLS has been negotiated successfully. (type: `bool`)
Instance Variable	allowInsecureLogin	An indication of whether plaintext login should be allowed when the server offers no authentication challenge and the transport does not offer any protection via encryption. (type: `bool`)
Instance Variable	serverChallenge	The challenge received in the server greeting. (type: `bytes` or `NoneType`)
Instance Variable	timeout	The number of seconds to wait on a response from the server before timing out a connection. If the number is <= 0, no timeout checking will be performed. (type: `int`)
Instance Variable	state	The state which indicates what type of response is expected from the server. Valid states are: 'WELCOME', 'WAITING', 'SHORT', 'LONG_INITIAL', 'LONG'. (type: `bytes`)
Method	sendShort	Send a POP3 command to which a short response is expected.
Method	sendLong	Send a POP3 command to which a multi-line response is expected.
Method	connectionMade	Wait for a greeting from the server after the connection has been made.
Method	timeoutConnection	Drop the connection when the server does not respond in time.
Method	connectionLost	Clean up when the connection has been lost.
Method	lineReceived	Pass a received line to a state machine function and transition to the next state.
Method	lineLengthExceeded	Drop the connection when a server response exceeds the maximum line length (`LineOnlyReceiver.MAX_LENGTH`).
Method	state_WELCOME	Handle server responses for the WELCOME state in which the server greeting is expected.
Method	state_WAITING	Log an error for server responses received in the WAITING state during which the server is not expected to send anything.
Method	state_SHORT	Handle server responses for the SHORT state in which the server is expected to send a single line response.
Method	state_LONG_INITIAL	Handle server responses for the LONG_INITIAL state in which the server is expected to send the first line of a multi-line response.
Method	state_LONG	Handle server responses for the LONG state in which the server is expected to send a non-initial line of a multi-line response.
Method	serverGreeting	Handle the server greeting.
Method	startTLS	Switch to encrypted communication using TLS.
Method	login	Log in to the server.
Method	apop	Send an APOP command to perform authenticated login.
Method	user	Send a USER command to perform the first half of plaintext login.
Method	password	Send a PASS command to perform the second half of plaintext login.
Method	delete	Send a DELE command to delete a message from the server.
Method	capabilities	Send a CAPA command to retrieve the capabilities supported by the server.
Method	noop	Send a NOOP command asking the server to do nothing but respond.
Method	reset	Send a RSET command to unmark any messages that have been flagged for deletion on the server.
Method	retrieve	Send a RETR or TOP command to retrieve all or part of a message from the server.
Method	stat	Send a STAT command to get information about the size of the mailbox.
Method	listSize	Send a LIST command to retrieve the sizes of all messages on the server.
Method	listUID	Send a UIDL command to retrieve the UIDs of all messages on the server.
Method	quit	Send a QUIT command to disconnect from the server.
Instance Variable	_capCache	The cached server capabilities. Capabilities are not allowed to change during the session (except when TLS is negotiated), so the first response to a capabilities command can be used for later lookups. (type: `NoneType` or `dict` mapping `bytes` to `list` of `bytes` and/or `bytes` to `NoneType`)
Instance Variable	_challengeMagicRe	A regular expression which matches the challenge in the server greeting. (type: `RegexObject`)
Instance Variable	_blockedQueue	A list of blocked commands. While a command is awaiting a response from the server, other commands are blocked. When no command is outstanding, `_blockedQueue` is set to `None`. Otherwise, it contains a list of information about blocked commands. Each list entry provides the following information about a blocked command: the deferred that should be called when the response to the command is received, the function that sends the command, and the arguments to the function. (type: `NoneType` or `list` of 3-`tuple` of (0) `Deferred`, (1) callable which results in a `Deferred`, (2) `tuple`)
Instance Variable	_waiting	A deferred which fires when the response to the outstanding command is received from the server. (type: `Deferred` or `NoneType`)
Instance Variable	_timedOut	An indication of whether the connection was dropped because of a timeout. (type: `bool`)
Instance Variable	_greetingError	The server greeting minus the status indicator, when the connection was dropped because of an error in the server greeting. Otherwise, `None`. (type: `bytes` or `NoneType`)
Instance Variable	_xform	The transform function which is used to convert each line of a multi-line response into usable values for use by the consumer function. If `None`, each line of the multi-line response is sent directly to the consumer function. (type: `NoneType` or callable that takes `bytes` and returns `object`)
Instance Variable	_consumer	The consumer function which is used to store the values derived by the transform function from each line of a multi-line response into a list. (type: callable that takes `object`)
Method	_blocked	Block a command, if necessary.
Method	_unblock	Send the next blocked command.
Method	_startTLS	Continue the process of switching to encrypted communication.
Method	_startedTLS	Complete the process of switching to encrypted communication.
Method	_getContextFactory	Get a context factory with which to negotiate TLS.
Method	_login	Continue the process of logging in to the server.
Method	_loginTLS	Do a plaintext login over an encrypted transport.
Method	_plaintext	Perform a plaintext login.
Method	_apop	Perform an APOP login.
Method	_consumeOrSetItem	Send a command to which a long response is expected and process the multi-line response into a list accounting for deleted messages.
Method	_consumeOrAppend	Send a command to which a long response is expected and process the multi-line response into a list.

Inherited from LineOnlyReceiver:

Class Variable	delimiter	The line-ending delimiter to use. By default this is `b'\r\n'`.
Class Variable	MAX_LENGTH	The maximum length of a line to allow (If a sent line is longer than this, the connection is dropped). Default is 16384.
Method	dataReceived	Translates bytes into lines, and calls lineReceived.
Method	sendLine	Sends a line to the other end of the connection.

Inherited from Protocol (via LineOnlyReceiver):

Method

logPrefix

Return a prefix matching the class name, to identify log messages related to this protocol instance.

Inherited from BaseProtocol (via LineOnlyReceiver, Protocol):

Method

makeConnection

Make a connection to a transport and a server.

Inherited from TimeoutMixin:

Class Variable	timeOut	The number of seconds after which to timeout the connection.
Method	callLater	Wrapper around `reactor.callLater` for test purpose.
Method	resetTimeout	Reset the timeout count down.
Method	setTimeout	Change the timeout period
Method	__timedOut	Undocumented

Block a command, if necessary.

If commands are being blocked, append information about the function which sends the command to a list and return a deferred that will be chained with the return value of the function when it eventually runs. Otherwise, set up for subsequent commands to be blocked and return None.

Parameters	f	A function which sends a command. (type: callable)
	a	Arguments to the function. (type: `tuple`)
Returns	`None` if the command can run immediately. Otherwise, a deferred that will eventually trigger with the return value of the function. (type: `NoneType` or `Deferred`)

Send the next blocked command.

If there are no more commands in the blocked queue, set up for the next command to be sent immediately.

Send a POP3 command to which a short response is expected.

Block all further commands from being sent until the response is received. Transition the state to SHORT.

Parameters	cmd	A POP3 command. (type: `bytes`)
	args	The command arguments. (type: `bytes`)
Returns	A deferred which fires when the entire response is received. On an OK response, it returns the response from the server minus the status indicator. On an ERR response, it issues a server error response failure with the response from the server minus the status indicator. (type: `Deferred` which successfully fires with `bytes` or fails with `ServerErrorResponse`)

Send a POP3 command to which a multi-line response is expected.

Block all further commands from being sent until the entire response is received. Transition the state to LONG_INITIAL.

Parameters	cmd	A POP3 command. (type: `bytes`)
	args	The command arguments. (type: `bytes`)
	consumer	A consumer function which should be used to put the values derived by a transform function from each line of the multi-line response into a list. (type: callable that takes `object`)
	xform	A transform function which should be used to transform each line of the multi-line response into usable values for use by a consumer function. If `None`, each line of the multi-line response should be sent directly to the consumer function. (type: `NoneType` or callable that takes `bytes` and returns `object`)
Returns	A deferred which fires when the entire response is received. On an OK response, it returns the consumer function. On an ERR response, it issues a server error response failure with the response from the server minus the status indicator and the consumer function. (type: `Deferred` which successfully fires with callable that takes `object` and fails with `ServerErrorResponse`)

Wait for a greeting from the server after the connection has been made.

Start the connection in the WELCOME state.

Drop the connection when the server does not respond in time.

Clean up when the connection has been lost.

When the loss of connection was initiated by the client due to a timeout, the _timedOut flag will be set. When it was initiated by the client due to an error in the server greeting, _greetingError will be set to the server response minus the status indicator.

Parameters reason The reason the connection was terminated. (type: Failure)

Pass a received line to a state machine function and transition to the next state.

Parameters line A received line. (type: bytes)

Drop the connection when a server response exceeds the maximum line length (LineOnlyReceiver.MAX_LENGTH).

Parameters buffer A received line which exceeds the maximum line length. (type: bytes)

Handle server responses for the WELCOME state in which the server greeting is expected.

WELCOME is the first state. The server should send one line of text with a greeting and possibly an APOP challenge. Transition the state to WAITING.

Parameters	line	A line received from the server. (type: `bytes`)
Returns	The next state. (type: `bytes`)

Log an error for server responses received in the WAITING state during which the server is not expected to send anything.

Parameters line A line received from the server. (type: bytes)

Handle server responses for the SHORT state in which the server is expected to send a single line response.

Parse the response and fire the deferred which is waiting on receipt of a complete response. Transition the state back to WAITING.

Parameters	line	A line received from the server. (type: `bytes`)
Returns	The next state. (type: `bytes`)

Handle server responses for the LONG_INITIAL state in which the server is expected to send the first line of a multi-line response.

Parse the response. On an OK response, transition the state to LONG. On an ERR response, cleanup and transition the state to WAITING.

Parameters	line	A line received from the server. (type: `bytes`)
Returns	The next state. (type: `bytes`)

Handle server responses for the LONG state in which the server is expected to send a non-initial line of a multi-line response.

On receipt of the last line of the response, clean up, fire the deferred which is waiting on receipt of a complete response, and transition the state to WAITING. Otherwise, pass the line to the transform function, if provided, and then the consumer function.

Parameters	line	A line received from the server. (type: `bytes`)
Returns	The next state. (type: `bytes`)

Handle the server greeting.

Parameters greeting The server greeting minus the status indicator. For servers implementing APOP authentication, this will contain a challenge string. (type: bytes)

Switch to encrypted communication using TLS.

The first step of switching to encrypted communication is obtaining the server's capabilities. When that is complete, the _startTLS callback function continues the switching process.

Parameters	contextFactory	The context factory with which to negotiate TLS. If not provided, try to create a new one. (type: `NoneType` or `ClientContextFactory`)
Returns	A deferred which fires when the transport has been secured according to the given context factory with the server capabilities, or which fails with a TLS error if the transport cannot be secured. (type: `Deferred` which successfully results in `dict` mapping `bytes` to `list` of `bytes` and/or `bytes` to `NoneType` or fails with `TLSError`)

Continue the process of switching to encrypted communication.

This callback function runs after the server capabilities are received.

The next step is sending the server an STLS command to request a switch to encrypted communication. When an OK response is received, the _startedTLS callback function completes the switch to encrypted communication. Then, the new server capabilities are requested.

Parameters	caps	The server capabilities. (type: `dict` mapping `bytes` to `list` of `bytes` and/or `bytes` to `NoneType`)
	contextFactory	A context factory with which to negotiate TLS. (type: `ClientContextFactory`)
	tls	A TCP transport that supports switching to TLS midstream. (type: `ITLSTransport`)
Returns	A deferred which successfully fires when the response from the server to the request to start TLS has been received and the new server capabilities have been received or fails when the server does not support TLS. (type: `Deferred` which successfully triggers with `dict` mapping `bytes` to `list` of `bytes` and/or `bytes` to `NoneType` or fails with `TLSNotSupportedError`)

Complete the process of switching to encrypted communication.

This callback function runs after the response to the STLS command has been received.

The final steps are discarding the cached capabilities and initiating TLS negotiation on the transport.

Parameters	result	The server capabilities. (type: `dict` mapping `bytes` to `list` of `bytes` and/or `bytes` to `NoneType`)
	context	A context factory with which to negotiate TLS. (type: `ClientContextFactory`)
	tls	A TCP transport that supports switching to TLS midstream. (type: `ITLSTransport`)
Returns	The server capabilities. (type: `dict` mapping `bytes` to `list` of `bytes` and/or `bytes` to `NoneType`)

Get a context factory with which to negotiate TLS.

Returns A context factory or None if TLS is not supported on the client. (type: NoneType or ClientContextFactory)

If APOP is available it will be used. Otherwise, if TLS is available, an encrypted session will be started and plaintext login will proceed. Otherwise, if allowInsecureLogin is set, insecure plaintext login will proceed. Otherwise, InsecureAuthenticationDisallowed will be raised.

The first step of logging into the server is obtaining the server's capabilities. When that is complete, the _login callback function continues the login process.

Parameters	username	The username with which to log in. (type: `bytes`)
	password	The password with which to log in. (type: `bytes`)
Returns	A deferred which fires when the login process is complete. On a successful login, it returns the server's response minus the status indicator. (type: `Deferred` which successfully fires with `bytes`)

Continue the process of logging in to the server.

This callback function runs after the server capabilities are received.

If the server provided a challenge in the greeting, proceed with an APOP login. Otherwise, if the server and the transport support encrypted communication, try to switch to TLS and then complete the login process with the _loginTLS callback function. Otherwise, if insecure authentication is allowed, do a plaintext login. Otherwise, fail with an InsecureAuthenticationDisallowed error.

Parameters	caps	The server capabilities. (type: `dict` mapping `bytes` to `list` of `bytes` and/or `bytes` to `NoneType`)
	username	The username with which to log in. (type: `bytes`)
	password	The password with which to log in. (type: `bytes`)
Returns	A deferred which fires when the login process is complete. On a successful login, it returns the server's response minus the status indicator. (type: `Deferred` which successfully fires with `bytes`)

Do a plaintext login over an encrypted transport.

This callback function runs after the transport switches to encrypted communication.

Parameters	res	The server capabilities. (type: `dict` mapping `bytes` to `list` of `bytes` and/or `bytes` to `NoneType`)
	username	The username with which to log in. (type: `bytes`)
	password	The password with which to log in. (type: `bytes`)
Returns	A deferred which fires when the server accepts the username and password or fails when the server rejects either. On a successful login, it returns the server's response minus the status indicator. (type: `Deferred` which successfully fires with `bytes` or fails with `ServerErrorResponse`)

Perform a plaintext login.

Parameters	username	The username with which to log in. (type: `bytes`)
	password	The password with which to log in. (type: `bytes`)
Returns	A deferred which fires when the server accepts the username and password or fails when the server rejects either. On a successful login, it returns the server's response minus the status indicator. (type: `Deferred` which successfully fires with `bytes` or fails with `ServerErrorResponse`)

Perform an APOP login.

Parameters	username	The username with which to log in. (type: `bytes`)
	password	The password with which to log in. (type: `bytes`)
	challenge	A challenge string. (type: `bytes`)
Returns	A deferred which fires when the server response is received. On a successful login, it returns the server response minus the status indicator. (type: `Deferred` which successfully fires with `bytes` or fails with `ServerErrorResponse`)

Send an APOP command to perform authenticated login.

This should be used in special circumstances only, when it is known that the server supports APOP authentication, and APOP authentication is absolutely required. For the common case, use login instead.

Parameters	username	The username with which to log in. (type: `bytes`)
	digest	The challenge response to authenticate with. (type: `bytes`)
Returns	A deferred which fires when the server response is received. On an OK response, the deferred succeeds with the server response minus the status indicator. On an ERR response, the deferred fails with a server error response failure. (type: `Deferred` which successfully fires with `bytes` or fails with `ServerErrorResponse`)

Send a USER command to perform the first half of plaintext login.

Unless this is absolutely required, use the login method instead.

Parameters	username	The username with which to log in. (type: `bytes`)
Returns	A deferred which fires when the server response is received. On an OK response, the deferred succeeds with the server response minus the status indicator. On an ERR response, the deferred fails with a server error response failure. (type: `Deferred` which successfully fires with `bytes` or fails with `ServerErrorResponse`)

Send a PASS command to perform the second half of plaintext login.

Unless this is absolutely required, use the login method instead.

Parameters	password	The plaintext password with which to authenticate. (type: `bytes`)
Returns	A deferred which fires when the server response is received. On an OK response, the deferred succeeds with the server response minus the status indicator. On an ERR response, the deferred fails with a server error response failure. (type: `Deferred` which successfully fires with `bytes` or fails with `ServerErrorResponse`)

Send a DELE command to delete a message from the server.

Parameters	index	The 0-based index of the message to delete. (type: `int`)
Returns	A deferred which fires when the server response is received. On an OK response, the deferred succeeds with the server response minus the status indicator. On an ERR response, the deferred fails with a server error response failure. (type: `Deferred` which successfully fires with `bytes` or fails with `ServerErrorResponse`)

Send a command to which a long response is expected and process the multi-line response into a list accounting for deleted messages.

Parameters	cmd	A POP3 command to which a long response is expected. (type: `bytes`)
	args	The command arguments. (type: `bytes`)
	consumer	`None` or a function that consumes the output from the transform function. (type: `NoneType` or callable that takes `object`)
	xform	A function that parses a line from a multi-line response and transforms the values into usable form for input to the consumer function. If no consumer function is specified, the output must be a message index and corresponding value. If no transform function is specified, the line is used as is. (type: `NoneType`, callable that takes `bytes` and returns 2-`tuple` of (0) `int`, (1) `object`, or callable that takes `bytes` and returns `object`)
Returns	A deferred which fires when the entire response has been received. When a consumer is not provided, the return value is a list of the value for each message or `None` for deleted messages. Otherwise, it returns the consumer itself. (type: `Deferred` which fires with `list` of `object` or callable that takes `list` of `object`)

Send a command to which a long response is expected and process the multi-line response into a list.

Parameters	cmd	A POP3 command which expects a long response. (type: `bytes`)
	args	The command arguments. (type: `bytes`)
	consumer	`None` or a function that consumes the output from the transform function. (type: `NoneType` or callable that takes `object`)
	xform	A function that transforms a line from a multi-line response into usable form for input to the consumer function. If no transform function is specified, the line is used as is. (type: `NoneType` or callable that takes `bytes` and returns `object`)
Returns	A deferred which fires when the entire response has been received. When a consumer is not provided, the return value is a list of the transformed lines. Otherwise, it returns the consumer itself. (type: `Deferred` which fires with `list` of 2-`tuple` of (0) `int`, (1) `object` or callable that takes 2-`tuple` of (0) `int`, (1) `object`)

Send a CAPA command to retrieve the capabilities supported by the server.

Not all servers support this command. If the server does not support this, it is treated as though it returned a successful response listing no capabilities. At some future time, this may be changed to instead seek out information about a server's capabilities in some other fashion (only if it proves useful to do so, and only if there are servers still in use which do not support CAPA but which do support POP3 extensions that are useful).

Parameters useCache A flag that determines whether previously retrieved results should be used if available. (type: bool)

Returns

A deferred which fires with a mapping of capability name to parameters. For example:

   C: CAPA
   S: +OK Capability list follows
   S: TOP
   S: USER
   S: SASL CRAM-MD5 KERBEROS_V4
   S: RESP-CODES
   S: LOGIN-DELAY 900
   S: PIPELINING
   S: EXPIRE 60
   S: UIDL
   S: IMPLEMENTATION Shlemazle-Plotz-v302
   S: .

will be lead to a result of:

   | {'TOP': None,
   |  'USER': None,
   |  'SASL': ['CRAM-MD5', 'KERBEROS_V4'],
   |  'RESP-CODES': None,
   |  'LOGIN-DELAY': ['900'],
   |  'PIPELINING': None,
   |  'EXPIRE': ['60'],
   |  'UIDL': None,
   |  'IMPLEMENTATION': ['Shlemazle-Plotz-v302']}

(type: Deferred which successfully results in dict mapping bytes to list of bytes and/or bytes to NoneType)

Send a NOOP command asking the server to do nothing but respond.

Returns A deferred which fires when the server response is received. On an OK response, the deferred succeeds with the server response minus the status indicator. On an ERR response, the deferred fails with a server error response failure. (type: Deferred which successfully fires with bytes or fails with ServerErrorResponse)

Send a RSET command to unmark any messages that have been flagged for deletion on the server.

Send a RETR or TOP command to retrieve all or part of a message from the server.

Parameters	index	A 0-based message index. (type: `int`)
	consumer	A function which consumes each transformed line from a multi-line response as it is received. (type: `NoneType` or callable that takes `bytes`)
	lines	If specified, the number of lines of the message to be retrieved. Otherwise, the entire message is retrieved. (type: `NoneType` or `int`)
Returns	A deferred which fires when the entire response has been received. When a consumer is not provided, the return value is a list of the transformed lines. Otherwise, it returns the consumer itself. (type: `Deferred` which fires with `list` of `bytes`, or callable that takes 2-`tuple` of (0) `int`, (1) `object`)

Send a STAT command to get information about the size of the mailbox.

Returns A deferred which fires when the server response is received. On an OK response, the deferred succeds with the number of messages in the mailbox and the size of the mailbox in octets. On an ERR response, the deferred fails with a server error response failure. (type: Deferred which successfully fires with a 2-tuple of (0) int, (1) int or fails with ServerErrorResponse)

Send a LIST command to retrieve the sizes of all messages on the server.

Parameters	consumer	A function which consumes the 0-based message index and message size derived from the server response. (type: `NoneType` or callable that takes 2-`tuple` of (0) `int`, (1) `int`)
Returns	A deferred which fires when the entire response has been received. When a consumer is not provided, the return value is a list of message sizes. Otherwise, it returns the consumer itself. (type: `Deferred` which fires `list` of `int` or callable that takes 2-`tuple` of (0) `int`, (1) `int`)

Send a UIDL command to retrieve the UIDs of all messages on the server.

Parameters	consumer	A function which consumes the 0-based message index and UID derived from the server response. (type: `NoneType` or callable that takes 2-`tuple` of (0) `int`, (1) `bytes`)
Returns	A deferred which fires when the entire response has been received. When a consumer is not provided, the return value is a list of message sizes. Otherwise, it returns the consumer itself. (type: `Deferred` which fires with `list` of `object` or callable that takes 2-`tuple` of (0) `int`, (1) `bytes`)

Send a QUIT command to disconnect from the server.

t.m.p.AdvancedPOP3Client(basic.LineOnlyReceiver, policies.TimeoutMixin) : class documentation