poplib — POP3 protocol client

Source code: Lib/poplib.py

This module defines a class, POP3, which encapsulates a connection to a POP3 server and implements the protocol as defined in RFC 1939. The POP3 class supports both the minimal and optional command sets from RFC 1939. The POP3 class also supports the STLS command introduced in RFC 2595 to enable encrypted communication on an already established connection.

Additionally, this module provides a class POP3_SSL, which provides support for connecting to POP3 servers that use SSL as an underlying protocol layer.

Note that POP3, though widely supported, is obsolescent. The implementation quality of POP3 servers varies widely, and too many are quite poor. If your mailserver supports IMAP, you would be better off using the imaplib.IMAP4 class, as IMAP servers tend to be better implemented.

Availability: not WASI.

This module does not work or is not available on WebAssembly. See WebAssembly platforms for more information.

The poplib module provides two classes:

class poplib.POP3(host, port=POP3_PORT[, timeout])

This class implements the actual POP3 protocol. The connection is created when the instance is initialized. If port is omitted, the standard POP3 port (110) is used. The optional timeout parameter specifies a timeout in seconds for the connection attempt (if not specified, the global default timeout setting will be used).

Raises an auditing event poplib.connect with arguments self, host, port.

All commands will raise an auditing event poplib.putline with arguments self and line, where line is the bytes about to be sent to the remote host.

Changed in version 3.9: If the timeout parameter is set to be zero, it will raise a ValueError to prevent the creation of a non-blocking socket.

class poplib.POP3_SSL(host, port=POP3_SSL_PORT, *, timeout=None, context=None)

This is a subclass of POP3 that connects to the server over an SSL encrypted socket. If port is not specified, 995, the standard POP3-over-SSL port is used. timeout works as in the POP3 constructor. context is an optional ssl.SSLContext object which allows bundling SSL configuration options, certificates and private keys into a single (potentially long-lived) structure. Please read Security considerations for best practices.

Raises an auditing event poplib.connect with arguments self, host, port.

All commands will raise an auditing event poplib.putline with arguments self and line, where line is the bytes about to be sent to the remote host.

Changed in version 3.2: context parameter added.

Changed in version 3.4: The class now supports hostname check with ssl.SSLContext.check_hostname and Server Name Indication (see