Source code:
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This module defines a class,
, which encapsulates a connection to a POP3 server and implements the protocol as defined in
. The POP3 class supports both the minimal and optional command sets from
. The POP3 class also supports the STLS command introduced in
to enable encrypted communication on an already established connection.
Additionally, this module provides a class
, 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
class, as IMAP servers tend to be better implemented.
The poplib module provides two classes:
classpoplib.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
poplib.connect with arguments self, host, port.
All commands will raise an
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
to prevent the creation of a non-blocking socket.
classpoplib.POP3_SSL(host, port=POP3_SSL_PORT, *, timeout=None, context=None)
This is a subclass of
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
object which allows bundling SSL configuration options, certificates and private keys into a single (potentially long-lived) structure. Please read
for best practices.
Raises an
poplib.connect with arguments self, host, port.
All commands will raise an
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 3.9: If the timeout parameter is set to be zero, it will raise a
to prevent the creation of a non-blocking socket.
Changed in version 3.12: The deprecated keyfile and certfile parameters have been removed.
One exception is defined as an attribute of the poplib module:
exceptionpoplib.error_proto
Exception raised on any errors from this module (errors from
module are not caught). The reason for the exception is passed to the constructor as a string.
See also
Module
The standard Python IMAP module.
Frequently Asked Questions About Fetchmail
The FAQ for the fetchmail POP/IMAP client collects information on POP3 server variations and RFC noncompliance that may be useful if you need to write an application based on the POP protocol.
POP3 Objects
All POP3 commands are represented by methods of the same name, in lowercase; most return the response text sent by the server.
A
instance has the following methods:
POP3.set_debuglevel(level)
Set the instance’s debugging level. This controls the amount of debugging output printed. The default, 0, produces no debugging output. A value of 1 produces a moderate amount of debugging output, generally a single line per request. A value of 2 or higher produces the maximum amount of debugging output, logging each line sent and received on the control connection.
POP3.getwelcome()
Returns the greeting string sent by the POP3 server.
POP3.capa()
Query the server’s capabilities as specified in
. Returns a dictionary in the form {'name':['param'...]}.
Added in version 3.4.
POP3.user(username)
Send user command, response should indicate that a password is required.
POP3.pass_(password)
Send password, response includes message count and mailbox size. Note: the mailbox on the server is locked until
is called.
POP3.apop(user, secret)
Use the more secure APOP authentication to log into the POP3 server.
POP3.rpop(user)
Use RPOP authentication (similar to UNIX r-commands) to log into POP3 server.
POP3.stat()
Get mailbox status. The result is a tuple of 2 integers: (messagecount,mailboxsize).
POP3.list([which])
Request message list, result is in the form (response,['mesg_numoctets',...],octets). If which is set, it is the message to list.
POP3.retr(which)
Retrieve whole message number which, and set its seen flag. Result is in form (response,['line',...],octets).
POP3.dele(which)
Flag message number which for deletion. On most servers deletions are not actually performed until QUIT (the major exception is Eudora QPOP, which deliberately violates the RFCs by doing pending deletes on any disconnect).
POP3.rset()
Remove any deletion marks for the mailbox.
POP3.noop()
Do nothing. Might be used as a keep-alive.
POP3.quit()
Signoff: commit changes, unlock mailbox, drop connection.
POP3.top(which, howmuch)
Retrieves the message header plus howmuch lines of the message after the header of message number which. Result is in form (response,['line',...],octets).
The POP3 TOP command this method uses, unlike the RETR command, doesn’t set the message’s seen flag; unfortunately, TOP is poorly specified in the RFCs and is frequently broken in off-brand servers. Test this method by hand against the POP3 servers you will use before trusting it.
POP3.uidl(which=None)
Return message digest (unique id) list. If which is specified, result contains the unique id for that message in the form 'responsemesgnumuid, otherwise result is list (response,['mesgnumuid',...],octets).
POP3.utf8()
Try to switch to UTF-8 mode. Returns the server response if successful, raises
if not. Specified in
.
Added in version 3.5.
POP3.stls(context=None)
Start a TLS session on the active connection as specified in
. This is only allowed before user authentication
context parameter is a
object which allows bundling SSL configuration options, certificates and private keys into a single (potentially long-lived) structure. Please read
for best practices.
This method supports hostname checking via
and Server Name Indication (see
).
Added in version 3.4.
Instances of
have no additional methods. The interface of this subclass is identical to its parent.
POP3 Example
Here is a minimal example (without error checking) that opens a mailbox and retrieves and prints all messages:
importgetpass,poplibM=poplib.POP3('localhost')M.user(getpass.getuser())M.pass_(getpass.getpass())numMessages=len(M.list()[1])foriinrange(numMessages):forjinM.retr(i+1)[1]:print(j)At the end of the module, there is a test section that contains a more extensive example of usage.