library/smtplib
smtplib
---SMTP协议客户端¶
源代码: Lib/smtplib.py
smtplib
模块定义了一个 SMTP 客户端会话对象,该对象可将邮件发送到 Internet 上带有 SMTP 或 ESMTP 接收程序的计算机。 关于 SMTP 和 ESMTP 操作的详情请参阅 RFC 821 (简单邮件传输协议) 和 RFC 1869 (SMTP 服务扩展)。
-
class
smtplib.
SMTP
(host='', port=0, local_hostname=None, [timeout, ]source_address=None)¶ 一个
SMTP
实例就是一个封装好的 SMTP 连接。该实例具有的方法支持所有 SMTP 和 ESMTP 操作。如果传入了可选参数 host 和 port,那么将在初始化时使用这些参数调用 SMTPconnect()
方法。如果传入了 local_hostname,它将在 HELO/EHLO 命令中被用作本地主机的 FQDN。否则将使用socket.getfqdn()
找到本地主机名。如果connect()
返回了成功码以外的内容,则引发SMTPConnectError
异常。可选参数 timeout 指定阻塞操作(如连接尝试)的超时(以秒为单位,如果未指定超时,将使用全局默认超时设置)。到达超时时长后会引发socket.timeout
异常。可选参数 source_address 允许在有多张网卡的计算机中绑定到某些特定的源地址,和/或绑定到某些特定的源 TCP 端口。在连接前,套接字需要绑定一个 2 元组 (host, port) 作为其源地址。如果省略,或者是主机为''
和/或端口为 0,则将使用操作系统默认行为。正常使用时,只需要初始化或 connect 方法,
sendmail()
方法,再加上SMTP.quit()
方法即可。下文包括了一个示例。SMTP
类支持with
语句。当这样使用时,with
语句一退出就会自动发出 SMTPQUIT
命令。例如:>>> from smtplib import SMTP >>> with SMTP("domain.org") as smtp: ... smtp.noop() ... (250, b'Ok') >>>
All commands will raise an auditing event
smtplib.SMTP.send
with argumentsself
anddata
, wheredata
is the bytes about to be sent to the remote host.在 3.3 版更改: 支持了
with
语句。在 3.3 版更改: source_address argument was added.
3.5 新版功能: The SMTPUTF8 extension (RFC 6531) is now supported.
在 3.9 版更改: If the timeout parameter is set to be zero, it will raise a
ValueError
to prevent the creation of a non-blocking socket
-
class
smtplib.
SMTP_SSL
(host='', port=0, local_hostname=None, keyfile=None, certfile=None, [timeout, ]context=None, source_address=None)¶ SMTP_SSL
实例与SMTP
实例的行为完全相同。在开始连接就需要 SSL,且starttls()
不适合的情况下,应该使用SMTP_SSL
。如果未指定 host,则使用 localhost。如果 port 为 0,则使用标准 SMTP-over-SSL 端口(465)。可选参数 local_hostname、timeout 和 source_address 的含义与SMTP
类中的相同。可选参数 context 是一个SSLContext
对象,可以从多个方面配置安全连接。请阅读 安全考量 以获取最佳实践。keyfile and certfile are a legacy alternative to context, and can point to a PEM formatted private key and certificate chain file for the SSL connection.
在 3.3 版更改: 增加了 context。
在 3.3 版更改: source_address argument was added.
在 3.4 版更改: 本类现在支持通过
ssl.SSLContext.check_hostname
和 服务器名称提示 (参阅ssl.HAS_SNI
)进行主机名检查。3.6 版后已移除: keyfile 和 certfile 已弃用并转而推荐 context。 请改用
ssl.SSLContext.load_cert_chain()
或让ssl.create_default_context()
为你选择系统所信任的 CA 证书。在 3.9 版更改: If the timeout parameter is set to be zero, it will raise a
ValueError
to prevent the creation of a non-blocking socket
-
class
smtplib.
LMTP
(host='', port=LMTP_PORT, local_hostname=None, source_address=None[, timeout])¶ LMTP 协议与 ESMTP 非常相似,它很大程度上基于标准的 SMTP 客户端。将 Unix 套接字用于 LMTP 是很常见的,因此
connect()
方法支持 Unix 套接字,也支持常规的 host:port 服务器。可选参数 local_hostname 和 source_address 的含义与SMTP
类中的相同。要指定 Unix 套接字,host 必须使用绝对路径,以 '/' 开头。Authentication is supported, using the regular SMTP mechanism. When using a Unix socket, LMTP generally don't support or require any authentication, but your mileage might vary.
在 3.9 版更改: The optional timeout parameter was added.
A nice selection of exceptions is defined as well:
-
exception
smtplib.
SMTPException
¶ Subclass of
OSError
that is the base exception class for all the other exceptions provided by this module.在 3.4 版更改: SMTPException became subclass of
OSError
-
exception
smtplib.
SMTPServerDisconnected
¶ This exception is raised when the server unexpectedly disconnects, or when an attempt is made to use the
SMTP
instance before connecting it to a server.
-
exception
smtplib.
SMTPResponseException
¶ Base class for all exceptions that include an SMTP error code. These exceptions are generated in some instances when the SMTP server returns an error code. The error code is stored in the
smtp_code
attribute of the error, and thesmtp_error
attribute is set to the error message.
-
exception
smtplib.
SMTPSenderRefused
¶ Sender address refused. In addition to the attributes set by on all
SMTPResponseException
exceptions, this sets 'sender' to the string that the SMTP server refused.
-
exception
smtplib.
SMTPRecipientsRefused
¶ All recipient addresses refused. The errors for each recipient are accessible through the attribute
recipients
, which is a dictionary of exactly the same sort asSMTP.sendmail()
returns.
-
exception
smtplib.
SMTPDataError
¶ The SMTP server refused to accept the message data.
-
exception
smtplib.
SMTPConnectError
¶ Error occurred during establishment of a connection with the server.
-
exception
smtplib.
SMTPHeloError
¶ The server refused our
HELO
message.
-
exception
smtplib.
SMTPNotSupportedError
¶ The command or option attempted is not supported by the server.
3.5 新版功能.
-
exception
smtplib.
SMTPAuthenticationError
¶ SMTP authentication went wrong. Most probably the server didn't accept the username/password combination provided.
参见
- RFC 821 - Simple Mail Transfer Protocol
Protocol definition for SMTP. This document covers the model, operating procedure, and protocol details for SMTP.
- RFC 1869 - SMTP Service Extensions
Definition of the ESMTP extensions for SMTP. This describes a framework for extending SMTP with new commands, supporting dynamic discovery of the commands provided by the server, and defines a few additional commands.
SMTP Objects¶
An SMTP
instance has the following methods:
-
SMTP.
set_debuglevel
(level)¶ Set the debug output level. A value of 1 or
True
for level results in debug messages for connection and for all messages sent to and received from the server. A value of 2 for level results in these messages being timestamped.在 3.5 版更改: Added debuglevel 2.
-
SMTP.
docmd
(cmd, args='')¶ Send a command cmd to the server. The optional argument args is simply concatenated to the command, separated by a space.
This returns a 2-tuple composed of a numeric response code and the actual response line (multiline responses are joined into one long line.)
In normal operation it should not be necessary to call this method explicitly. It is used to implement other methods and may be useful for testing private extensions.
If the connection to the server is lost while waiting for the reply,
SMTPServerDisconnected
will be raised.
-
SMTP.
connect
(host='localhost', port=0)¶ 连接到某个主机的某个端口。默认是连接到 localhost 的标准 SMTP 端口(25)上。如果主机名以冒号 (
':'
) 结尾,后跟数字,则该后缀将被删除,且数字将视作要使用的端口号。如果在实例化时指定了 host,则构造函数会自动调用本方法。返回包含响应码和响应消息的 2 元组,它们由服务器在其连接响应中发送。Raises an auditing event
smtplib.connect
with argumentsself
,host
,port
.
-
SMTP.
helo
(name='')¶ Identify yourself to the SMTP server using
HELO
. The hostname argument defaults to the fully qualified domain name of the local host. The message returned by the server is stored as thehelo_resp
attribute of the object.In normal operation it should not be necessary to call this method explicitly. It will be implicitly called by the
sendmail()
when necessary.
-
SMTP.
ehlo
(name='')¶ 使用
EHLO
向 ESMTP 服务器标识自身。hostname 参数默认为 localhost 的标准域名。使用has_extn()
来检查响应中的 ESMTP 选项,并将它们保存起来。还给一些信息性的属性赋值:服务器返回的消息存储为ehlo_resp
属性;根据服务器是否支持 ESMTP,将does_esmtp
设置为 true 或 false;而esmtp_features
是一个字典,包含该服务器支持的 SMTP 服务扩展的名称及参数(如果有参数)。Unless you wish to use
has_extn()
before sending mail, it should not be necessary to call this method explicitly. It will be implicitly called bysendmail()
when necessary.
-
SMTP.
ehlo_or_helo_if_needed
()¶ This method calls
ehlo()
and/orhelo()
if there has been no previousEHLO
orHELO
command this session. It tries ESMTPEHLO
first.SMTPHeloError
The server didn't reply properly to the
HELO
greeting.
-
SMTP.
has_extn
(name)¶ Return
True
if name is in the set of SMTP service extensions returned by the server,False
otherwise. Case is ignored.
-
SMTP.
verify
(address)¶ Check the validity of an address on this server using SMTP
VRFY
. Returns a tuple consisting of code 250 and a full RFC 822 address (including human name) if the user address is valid. Otherwise returns an SMTP error code of 400 or greater and an error string.注解
Many sites disable SMTP
VRFY
in order to foil spammers.
-
SMTP.
login
(user, password, *, initial_response_ok=True)¶ Log in on an SMTP server that requires authentication. The arguments are the username and the password to authenticate with. If there has been no previous
EHLO
orHELO
command this session, this method tries ESMTPEHLO
first. This method will return normally if the authentication was successful, or may raise the following exceptions:SMTPHeloError
The server didn't reply properly to the
HELO
greeting.SMTPAuthenticationError
The server didn't accept the username/password combination.
SMTPNotSupportedError
The
AUTH
command is not supported by the server.SMTPException
No suitable authentication method was found.
Each of the authentication methods supported by
smtplib
are tried in turn if they are advertised as supported by the server. Seeauth()
for a list of supported authentication methods. initial_response_ok is passed through toauth()
.Optional keyword argument initial_response_ok specifies whether, for authentication methods that support it, an "initial response" as specified in RFC 4954 can be sent along with the
AUTH
command, rather than requiring a challenge/response.在 3.5 版更改:
SMTPNotSupportedError
may be raised, and the initial_response_ok parameter was added.
-
SMTP.
auth
(mechanism, authobject, *, initial_response_ok=True)¶ Issue an
SMTP
AUTH
command for the specified authentication mechanism, and handle the challenge response via authobject.mechanism specifies which authentication mechanism is to be used as argument to the
AUTH
command; the valid values are those listed in theauth
element ofesmtp_features
.authobject must be a callable object taking an optional single argument:
data = authobject(challenge=None)
If optional keyword argument initial_response_ok is true,
authobject()
will be called first with no argument. It can return the RFC 4954 "initial response" ASCIIstr
which will be encoded and sent with theAUTH
command as below. If theauthobject()
does not support an initial response (e.g. because it requires a challenge), it should returnNone
when called withchallenge=None
. If initial_response_ok is false, thenauthobject()
will not be called first withNone
.If the initial response check returns
None
, or if initial_response_ok is false,authobject()
will be called to process the server's challenge response; the challenge argument it is passed will be abytes
. It should return ASCIIstr
data that will be base64 encoded and sent to the server.The
SMTP
class providesauthobjects
for theCRAM-MD5
,PLAIN
, andLOGIN
mechanisms; they are namedSMTP.auth_cram_md5
,SMTP.auth_plain
, andSMTP.auth_login
respectively. They all require that theuser
andpassword
properties of theSMTP
instance are set to appropriate values.User code does not normally need to call
auth
directly, but can instead call thelogin()
method, which will try each of the above mechanisms in turn, in the order listed.auth
is exposed to facilitate the implementation of authentication methods not (or not yet) supported directly bysmtplib
.3.5 新版功能.
-
SMTP.
starttls
(keyfile=None, certfile=None, context=None)¶ Put the SMTP connection in TLS (Transport Layer Security) mode. All SMTP commands that follow will be encrypted. You should then call
ehlo()
again.If keyfile and certfile are provided, they are used to create an
ssl.SSLContext
.Optional context parameter is an
ssl.SSLContext
object; This is an alternative to using a keyfile and a certfile and if specified both keyfile and certfile should beNone
.If there has been no previous
EHLO
orHELO
command this session, this method tries ESMTPEHLO
first.3.6 版后已移除: keyfile 和 certfile 已弃用并转而推荐 context。 请改用
ssl.SSLContext.load_cert_chain()
或让ssl.create_default_context()
为你选择系统所信任的 CA 证书。SMTPHeloError
The server didn't reply properly to the
HELO
greeting.SMTPNotSupportedError
The server does not support the STARTTLS extension.
RuntimeError
SSL/TLS support is not available to your Python interpreter.
在 3.3 版更改: 增加了 context。
在 3.4 版更改: The method now supports hostname check with
SSLContext.check_hostname
and Server Name Indicator (seeHAS_SNI
).在 3.5 版更改: The error raised for lack of STARTTLS support is now the
SMTPNotSupportedError
subclass instead of the baseSMTPException
.
-
SMTP.
sendmail
(from_addr, to_addrs, msg, mail_options=(), rcpt_options=())¶ 发送邮件。必要参数是一个 RFC 822 发件地址字符串,一个 RFC 822 收件地址字符串列表(裸字符串将被视为含有 1 个地址的列表),以及一个消息字符串。调用者可以将 ESMTP 选项列表(如
8bitmime
)作为 mail_options 传入,用于MAIL FROM
命令。需要与所有RCPT
命令一起使用的 ESMTP 选项(如DSN
命令)可以作为 rcpt_options 传入。(如果需要对不同的收件人使用不同的 ESMTP 选项,则必须使用底层的方法来发送消息,如mail()
,rcpt()
和data()
。)注解
The from_addr and to_addrs parameters are used to construct the message envelope used by the transport agents.
sendmail
does not modify the message headers in any way.msg may be a string containing characters in the ASCII range, or a byte string. A string is encoded to bytes using the ascii codec, and lone
\r
and\n
characters are converted to\r\n
characters. A byte string is not modified.If there has been no previous
EHLO
orHELO
command this session, this method tries ESMTPEHLO
first. If the server does ESMTP, message size and each of the specified options will be passed to it (if the option is in the feature set the server advertises). IfEHLO
fails,HELO
will be tried and ESMTP options suppressed.This method will return normally if the mail is accepted for at least one recipient. Otherwise it will raise an exception. That is, if this method does not raise an exception, then someone should get your mail. If this method does not raise an exception, it returns a dictionary, with one entry for each recipient that was refused. Each entry contains a tuple of the SMTP error code and the accompanying error message sent by the server.
If
SMTPUTF8
is included in mail_options, and the server supports it, from_addr and to_addrs may contain non-ASCII characters.This method may raise the following exceptions:
SMTPRecipientsRefused
All recipients were refused. Nobody got the mail. The
recipients
attribute of the exception object is a dictionary with information about the refused recipients (like the one returned when at least one recipient was accepted).SMTPHeloError
The server didn't reply properly to the
HELO
greeting.SMTPSenderRefused
The server didn't accept the from_addr.
SMTPDataError
The server replied with an unexpected error code (other than a refusal of a recipient).
SMTPNotSupportedError
SMTPUTF8
was given in the mail_options but is not supported by the server.
Unless otherwise noted, the connection will be open even after an exception is raised.
在 3.2 版更改: msg may be a byte string.
在 3.5 版更改:
SMTPUTF8
support added, andSMTPNotSupportedError
may be raised ifSMTPUTF8
is specified but the server does not support it.
-
SMTP.
send_message
(msg, from_addr=None, to_addrs=None, mail_options=(), rcpt_options=())¶ 本方法是一种快捷方法,用于带着消息调用
sendmail()
,消息由email.message.Message
对象表示。参数的含义与sendmail()
中的相同,除了 msg,它是一个Message
对象。如果 from_addr 为
None
或 to_addrs 为None
,那么``send_message``将根据 RFC 5322,从 msg 头部提取地址填充下列参数:如果头部存在 Sender 字段,则用它填充 from_addr,不存在则用 From 字段填充 from_addr。to_addrs 组合了 msg 中的 To, Cc 和 Bcc 字段的值(字段存在的情况下)。如果一组 Resent-* 头部恰好出现在 message 中,那么就忽略常规的头部,改用 Resent-* 头部。如果 message 包含多组 Resent-* 头部,则引发ValueError
,因为无法明确检测出哪一组 Resent- 头部是最新的。send_message
使用BytesGenerator
来序列化 msg,且将\r\n
作为 linesep,并调用sendmail()
来传输序列化后的结果。无论 from_addr 和 to_addrs 的值为何,send_message
都不会传输 msg 中可能出现的 Bcc 或 Resent-Bcc 头部。如果 from_addr 和 to_addrs 中的某个地址包含非 ASCII 字符,且服务器没有声明支持SMTPUTF8
,则引发SMTPNotSupported
错误。如果服务器支持,则Message
将按新克隆的policy
进行序列化,其中的utf8
属性被设置为True
,且SMTPUTF8
和BODY=8BITMIME
被添加到 mail_options 中。3.2 新版功能.
3.5 新版功能: Support for internationalized addresses (
SMTPUTF8
).
-
SMTP.
quit
()¶ Terminate the SMTP session and close the connection. Return the result of the SMTP
QUIT
command.
Low-level methods corresponding to the standard SMTP/ESMTP commands HELP
,
RSET
, NOOP
, MAIL
, RCPT
, and DATA
are also supported.
Normally these do not need to be called directly, so they are not documented
here. For details, consult the module code.
SMTP Example¶
This example prompts the user for addresses needed in the message envelope ('To' and 'From' addresses), and the message to be delivered. Note that the headers to be included with the message must be included in the message as entered; this example doesn't do any processing of the RFC 822 headers. In particular, the 'To' and 'From' addresses must be included in the message headers explicitly.
import smtplib
def prompt(prompt):
return input(prompt).strip()
fromaddr = prompt("From: ")
toaddrs = prompt("To: ").split()
print("Enter message, end with ^D (Unix) or ^Z (Windows):")
# Add the From: and To: headers at the start!
msg = ("From: %s\r\nTo: %s\r\n\r\n"
% (fromaddr, ", ".join(toaddrs)))
while True:
try:
line = input()
except EOFError:
break
if not line:
break
msg = msg + line
print("Message length is", len(msg))
server = smtplib.SMTP('localhost')
server.set_debuglevel(1)
server.sendmail(fromaddr, toaddrs, msg)
server.quit()
注解
In general, you will want to use the email
package's features to
construct an email message, which you can then send
via send_message()
; see email: 示例.
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