# Poco::Net

# class POP3ClientSession

Library: Net
Package: Mail
Header: Poco/Net/POP3ClientSession.h

## Description

This class implements an Post Office Protocol Version 3 (POP3, RFC 1939) client for receiving e-mail messages.

## Member Summary

Member Functions: close, deleteMessage, getTimeout, isPositive, listMessages, login, messageCount, retrieveHeader, retrieveMessage, sendCommand, setTimeout

## Nested Classes

### struct MessageInfo

Information returned by listMessages().

## Types Aliases

### MessageInfoVec

using MessageInfoVec = std::vector < MessageInfo >;

## Enumerations

### Anonymous

POP3_PORT = 110

## Constructors

### POP3ClientSession

explicit POP3ClientSession(
const StreamSocket & socket
);

Creates the POP3ClientSession using the given socket, which must be connected to a POP3 server.

### POP3ClientSession

POP3ClientSession(
const std::string & host,
Poco::UInt16 port = POP3_PORT
);

Creates the POP3ClientSession using a socket connected to the given host and port.

## Destructor

### ~POP3ClientSession

virtual ~POP3ClientSession();

Destroys the SMTPClientSession.

## Member Functions

### close

void close();

Sends a QUIT command and closes the connection to the server.

Throws a POP3Exception in case of a POP3-specific error, or a NetException in case of a general network communication failure.

### deleteMessage

void deleteMessage(
int id
);

Marks the message with the given ID for deletion. The message will be deleted when the connection to the server is closed by calling close().

Throws a POP3Exception in case of a POP3-specific error, or a NetException in case of a general network communication failure.

### getTimeout

Poco::Timespan getTimeout() const;

Returns the timeout for socket read operations.

### listMessages

void listMessages(
MessageInfoVec & messages
);

Fills the given vector with the ids and sizes of all messages available on the server.

Throws a POP3Exception in case of a POP3-specific error, or a NetException in case of a general network communication failure.

### login

void login(
const std::string & username,
const std::string & password
);

Logs in to the POP3 server by sending a USER command followed by a PASS command.

Throws a POP3Exception in case of a POP3-specific error, or a NetException in case of a general network communication failure.

### messageCount

int messageCount();

Sends a STAT command to determine the number of messages available on the server and returns that number.

Throws a POP3Exception in case of a POP3-specific error, or a NetException in case of a general network communication failure.

### retrieveHeader

void retrieveHeader(
int id,
MessageHeader & header
);

Retrieves the message header of the message with the given id and stores it in header.

For this to work, the server must support the TOP command.

Throws a POP3Exception in case of a POP3-specific error, or a NetException in case of a general network communication failure.

### retrieveMessage

void retrieveMessage(
int id,
MailMessage & message
);

Retrieves the message with the given id from the server and stores the raw message content in the message's content string, available with message.getContent().

Throws a POP3Exception in case of a POP3-specific error, or a NetException in case of a general network communication failure.

### retrieveMessage

void retrieveMessage(
int id,
MailMessage & message,
PartHandler & handler
);

Retrieves the message with the given id from the server and stores it in message.

If the message has multiple parts, the parts are reported to the PartHandler. If the message is not a multi-part message, the content is stored in a string available by calling message.getContent().

Throws a POP3Exception in case of a POP3-specific error, or a NetException in case of a general network communication failure.

### retrieveMessage

void retrieveMessage(
int id,
std::ostream & ostr
);

Retrieves the raw message with the given id from the server and copies it to the given output stream.

Throws a POP3Exception in case of a POP3-specific error, or a NetException in case of a general network communication failure.

### sendCommand

bool sendCommand(
const std::string & command,
std::string & response
);

Sends the given command verbatim to the server and waits for a response.

Returns true if the response is positive, false otherwise.

Throws a POP3Exception in case of a POP3-specific error, or a NetException in case of a general network communication failure.

### sendCommand

bool sendCommand(
const std::string & command,
const std::string & arg,
std::string & response
);

Sends the given command verbatim to the server and waits for a response.

Returns true if the response is positive, false otherwise.

Throws a POP3Exception in case of a POP3-specific error, or a NetException in case of a general network communication failure.

### sendCommand

bool sendCommand(
const std::string & command,
const std::string & arg1,
const std::string & arg2,
std::string & response
);

Sends the given command verbatim to the server and waits for a response.

Returns true if the response is positive, false otherwise.

Throws a POP3Exception in case of a POP3-specific error, or a NetException in case of a general network communication failure.

### setTimeout

void setTimeout(
const Poco::Timespan & timeout
);

Sets the timeout for socket read operations.

### isPositive

static bool isPositive(
const std::string & response
);