#! /usr/bin/python3.9
'''SMTP/ESMTP client class.
This should follow RFC 821 (SMTP), RFC 1869 (ESMTP), RFC 2554 (SMTP
Authentication) and RFC 2487 (Secure SMTP over TLS).
Notes:
Please remember, when doing ESMTP, that the names of the SMTP service
extensions are NOT the same thing as the option keywords for the RCPT
and MAIL commands!
Example:
>>> import smtplib
>>> s=smtplib.SMTP("localhost")
>>> print(s.help())
This is Sendmail version 8.8.4
Topics:
HELO EHLO MAIL RCPT DATA
RSET NOOP QUIT HELP VRFY
EXPN VERB ETRN DSN
For more info use "HELP <topic>".
To report bugs in the implementation send email to
sendmail-bugs@sendmail.org.
For local information send email to Postmaster at your site.
End of HELP info
>>> s.putcmd("vrfy","someone@here")
>>> s.getreply()
(250, "Somebody OverHere <somebody@here.my.org>")
>>> s.quit()
'''
# Author: The Dragon De Monsyne <dragondm@integral.org>
# ESMTP support, test code and doc fixes added by
# Eric S. Raymond <esr@thyrsus.com>
# Better RFC 821 compliance (MAIL and RCPT, and CRLF in data)
# by Carey Evans <c.evans@clear.net.nz>, for picky mail servers.
# RFC 2554 (authentication) support by Gerhard Haering <gerhard@bigfoot.de>.
#
# This was modified from the Python 1.5 library HTTP lib.
import socket
import io
import re
import email.utils
import email.message
import email.generator
import base64
import hmac
import copy
import datetime
import sys
from email.base64mime import body_encode as encode_base64
__all__ = ["SMTPException", "SMTPNotSupportedError", "SMTPServerDisconnected", "SMTPResponseException",
"SMTPSenderRefused", "SMTPRecipientsRefused", "SMTPDataError",
"SMTPConnectError", "SMTPHeloError", "SMTPAuthenticationError",
"quoteaddr", "quotedata", "SMTP"]
SMTP_PORT = 25
SMTP_SSL_PORT = 465
CRLF = "\r\n"
bCRLF = b"\r\n"
_MAXLINE = 8192 # more than 8 times larger than RFC 821, 4.5.3
_MAXCHALLENGE = 5 # Maximum number of AUTH challenges sent
OLDSTYLE_AUTH = re.compile(r"auth=(.*)", re.I)
# Exception classes used by this module.
class SMTPException(OSError):
"""Base class for all exceptions raised by this module."""
class SMTPNotSupportedError(SMTPException):
"""The command or option is not supported by the SMTP server.
This exception is raised when an attempt is made to run a command or a
command with an option which is not supported by the server.
"""
class SMTPServerDisconnected(SMTPException):
"""Not connected to any SMTP server.
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.
"""
class SMTPResponseException(SMTPException):
"""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 the `smtp_error' attribute
is set to the error message.
"""
def __init__(self, code, msg):
self.smtp_code = code
self.smtp_error = msg
self.args = (code, msg)
class SMTPSenderRefused(SMTPResponseException):
"""Sender address refused.
In addition to the attributes set by on all SMTPResponseException
exceptions, this sets `sender' to the string that the SMTP refused.
"""
def __init__(self, code, msg, sender):
self.smtp_code = code
self.smtp_error = msg
self.sender = sender
self.args = (code, msg, sender)
class SMTPRecipientsRefused(SMTPException):
"""All recipient addresses refused.
The errors for each recipient are accessible through the attribute
'recipients', which is a dictionary of exactly the same sort as
SMTP.sendmail() returns.
"""
def __init__(self, recipients):
self.recipients = recipients
self.args = (recipients,)
class SMTPDataError(SMTPResponseException):
"""The SMTP server didn't accept the data."""
class SMTPConnectError(SMTPResponseException):
"""Error during connection establishment."""
class SMTPHeloError(SMTPResponseException):
"""The server refused our HELO reply."""
class SMTPAuthenticationError(SMTPResponseException):
"""Authentication error.
Most probably the server didn't accept the username/password
combination provided.
"""
def quoteaddr(addrstring):
"""Quote a subset of the email addresses defined by RFC 821.
Should be able to handle anything email.utils.parseaddr can handle.
"""
displayname, addr = email.utils.parseaddr(addrstring)
if (displayname, addr) == ('', ''):
# parseaddr couldn't parse it, use it as is and hope for the best.
if addrstring.strip().startswith('<'):
return addrstring
return "<%s>" % addrstring
return "<%s>" % addr
def _addr_only(addrstring):
displayname, addr = email.utils.parseaddr(addrstring)
if (displayname, addr) == ('', ''):
# parseaddr couldn't parse it, so use it as is.
return addrstring
return addr
# Legacy method kept for backward compatibility.
def quotedata(data):
"""Quote data for email.
Double leading '.', and change Unix newline '\\n', or Mac '\\r' into
Internet CRLF end-of-line.
"""
return re.sub(r'(?m)^\.', '..',
re.sub(r'(?:\r\n|\n|\r(?!\n))', CRLF, data))
def _quote_periods(bindata):
return re.sub(br'(?m)^\.', b'..', bindata)
def _fix_eols(data):
return re.sub(r'(?:\r\n|\n|\r(?!\n))', CRLF, data)
try:
import ssl
except ImportError:
_have_ssl = False
else:
_have_ssl = True
class SMTP:
"""This class manages a connection to an SMTP or ESMTP server.
SMTP Objects:
SMTP objects have the following attributes:
helo_resp
This is the message given by the server in response to the
most recent HELO command.
ehlo_resp
This is the message given by the server in response to the
most recent EHLO command. This is usually multiline.
does_esmtp
This is a True value _after you do an EHLO command_, if the
server supports ESMTP.
esmtp_features
This is a dictionary, which, if the server supports ESMTP,
will _after you do an EHLO command_, contain the names of the
SMTP service extensions this server supports, and their
parameters (if any).
Note, all extension names are mapped to lower case in the
dictionary.
See each method's docstrings for details. In general, there is a
method of the same name to perform each SMTP command. There is also a
method called 'sendmail' that will do an entire mail transaction.
"""
debuglevel = 0
sock = None
file = None
helo_resp = None
ehlo_msg = "ehlo"
ehlo_resp = None
does_esmtp = 0
default_port = SMTP_PORT
def __init__(self, host='', port=0, local_hostname=None,
timeout=socket._GLOBAL_DEFAULT_TIMEOUT,
source_address=None):
"""Initialize a new instance.
If specified, `host` is the name of the remote host to which to
connect. If specified, `port` specifies the port to which to connect.
By default, smtplib.SMTP_PORT is used. If a host is specified the
connect method is called, and if it returns anything other than a
success code an SMTPConnectError is raised. If specified,
`local_hostname` is used as the FQDN of the local host in the HELO/EHLO
command. Otherwise, the local hostname is found using
socket.getfqdn(). The `source_address` parameter takes a 2-tuple (host,
port) for the socket to bind to as its source address before
connecting. If the host is '' and port is 0, the OS default behavior
will be used.
"""
self._host = host
self.timeout = timeout
self.esmtp_features = {}
self.command_encoding = 'ascii'
self.source_address = source_address
self._auth_challenge_count = 0
if host:
(code, msg) = self.connect(host, port)
if code != 220:
self.close()
raise SMTPConnectError(code, msg)
if local_hostname is not None:
self.local_hostname = local_hostname
else:
# RFC 2821 says we should use the fqdn in the EHLO/HELO verb, and
# if that can't be calculated, that we should use a domain literal
# instead (essentially an encoded IP address like [A.B.C.D]).
fqdn = socket.getfqdn()
if '.' in fqdn:
self.local_hostname = fqdn
else:
# We can't find an fqdn hostname, so use a domain literal
addr = '127.0.0.1'
try:
addr = socket.gethostbyname(socket.gethostname())
except socket.gaierror:
pass
self.local_hostname = '[%s]' % addr
def __enter__(self):
return self
def __exit__(self, *args):
try:
code, message = self.docmd("QUIT")
if code != 221:
raise SMTPResponseException(code, message)
except SMTPServerDisconnected:
pass
finally:
self.close()
def set_debuglevel(self, debuglevel):
"""Set the debug output level.
A non-false value results in debug messages for connection and for all
messages sent to and received from the server.
"""
self.debuglevel = debuglevel
def _print_debug(self, *args):
if self.debuglevel > 1:
print(datetime.datetime.now().time(), *args, file=sys.stderr)
else:
print(*args, file=sys.stderr)
def _get_socket(self, host, port, timeout):
# This makes it simpler for SMTP_SSL to use the SMTP connect code
# and just alter the socket connection bit.
if timeout is not None and not timeout:
raise ValueError('Non-blocking socket (timeout=0) is not supported')
if self.debuglevel > 0:
self._print_debug('connect: to', (host, port), self.source_address)
return socket.create_connection((host, port), timeout,
self.source_address)
def connect(self, host='localhost', port=0, source_address=None):
"""Connect to a host on a given port.
If the hostname ends with a colon (`:') followed by a number, and
there is no port specified, that suffix will be stripped off and the
number interpreted as the port number to use.
Note: This method is automatically invoked by __init__, if a host is
specified during instantiation.
"""
if source_address:
self.source_address = source_address
if not port and (host.find(':') == host.rfind(':')):
i = host.rfind(':')
if i >= 0:
host, port = host[:i], host[i + 1:]
try:
port = int(port)
except ValueError:
raise OSError("nonnumeric port")
if not port:
port = self.default_port
sys.audit("smtplib.connect", self, host, port)
self.sock = self._get_socket(host, port, self.timeout)
self.file = None
(code, msg) = self.getreply()
if self.debuglevel > 0:
self._print_debug('connect:', repr(msg))
return (code, msg)
def send(self, s):
"""Send `s' to the server."""
if self.debuglevel > 0:
self._print_debug('send:', repr(s))
if self.sock:
if isinstance(s, str):
# send is used by the 'data' command, where command_encoding
# should not be used, but 'data' needs to convert the string to
# binary itself anyway, so that's not a problem.
s = s.encode(self.command_encoding)
sys.audit("smtplib.send", self, s)
try:
self.sock.sendall(s)
except OSError:
self.close()
raise SMTPServerDisconnected('Server not connected')
else:
raise SMTPServerDisconnected('please run connect() first')
def putcmd(self, cmd, args=""):
"""Send a command to the server."""
if args == "":
s = cmd
else:
s = f'{cmd} {args}'
if '\r' in s or '\n' in s:
s = s.replace('\n', '\\n').replace('\r', '\\r')
raise ValueError(
f'command and arguments contain prohibited newline characters: {s}'
)
self.send(f'{s}{CRLF}')
def getreply(self):
"""Get a reply from the server.
Returns a tuple consisting of:
- server response code (e.g. '250', or such, if all goes well)
Note: returns -1 if it can't read response code.
- server response string corresponding to response code (multiline
responses are converted to a single, multiline string).
Raises SMTPServerDisconnected if end-of-file is reached.
"""
resp = []
if self.file is None:
self.file = self.sock.makefile('rb')
while 1:
try:
line = self.file.readline(_MAXLINE + 1)
except OSError as e:
self.close()
raise SMTPServerDisconnected("Connection unexpectedly closed: "
+ str(e))
if not line:
self.close()
raise SMTPServerDisconnected("Connection unexpectedly closed")
if self.debuglevel > 0:
self._print_debug('reply:', repr(line))
if len(line) > _MAXLINE:
self.close()
raise SMTPResponseException(500, "Line too long.")
resp.append(line[4:].strip(b' \t\r\n'))
code = line[:3]
# Check that the error code is syntactically correct.
# Don't attempt to read a continuation line if it is broken.
try:
errcode = int(code)
except ValueError:
errcode = -1
break
# Check if multiline response.
if line[3:4] != b"-":
break
errmsg = b"\n".join(resp)
if self.debuglevel > 0:
self._print_debug('reply: retcode (%s); Msg: %a' % (errcode, errmsg))
return errcode, errmsg
def docmd(self, cmd, args=""):
"""Send a command, and return its response code."""
self.putcmd(cmd, args)
return self.getreply()
# std smtp commands
def helo(self, name=''):
"""SMTP 'helo' command.
Hostname to send for this command defaults to the FQDN of the local
host.
"""
self.putcmd("helo", name or self.local_hostname)
(code, msg) = self.getreply()
self.helo_resp = msg
return (code, msg)
def ehlo(self, name=''):
""" SMTP 'ehlo' command.
Hostname to send for this command defaults to the FQDN of the local
host.
"""
self.esmtp_features = {}
self.putcmd(self.ehlo_msg, name or self.local_hostname)
(code, msg) = self.getreply()
# According to RFC1869 some (badly written)
# MTA's will disconnect on an ehlo. Toss an exception if
# that happens -ddm
if code == -1 and len(msg) == 0:
self.close()
raise SMTPServerDisconnected("Server not connected")
self.ehlo_resp = msg
if code != 250:
return (code, msg)
self.does_esmtp = 1
#parse the ehlo response -ddm
assert isinstance(self.ehlo_resp, bytes), repr(self.ehlo_resp)
resp = self.ehlo_resp.decode("latin-1").split('\n')
del resp[0]
for each in resp:
# To be able to communicate with as many SMTP servers as possible,
# we have to take the old-style auth advertisement into account,
# because:
# 1) Else our SMTP feature parser gets confused.
# 2) There are some servers that only advertise the auth methods we
# support using the old style.
auth_match = OLDSTYLE_AUTH.match(each)
if auth_match:
# This doesn't remove duplicates, but that's no problem
self.esmtp_features["auth"] = self.esmtp_features.get("auth", "") \
+ " " + auth_match.groups(0)[0]
continue
# RFC 1869 requires a space between ehlo keyword and parameters.
# It's actually stricter, in that only spaces are allowed between
# parameters, but were not going to check for that here. Note
# that the space isn't present if there are no parameters.
m = re.match(r'(?P<feature>[A-Za-z0-9][A-Za-z0-9\-]*) ?', each)
if m:
feature = m.group("feature").lower()
params = m.string[m.end("feature"):].strip()
if feature == "auth":
self.esmtp_features[feature] = self.esmtp_features.get(feature, "") \
+ " " + params
else:
self.esmtp_features[feature] = params
return (code, msg)
def has_extn(self, opt):
"""Does the server support a given SMTP service extension?"""
return opt.lower() in self.esmtp_features
def help(self, args=''):
"""SMTP 'help' command.
Returns help text from server."""
self.putcmd("help", args)
return self.getreply()[1]
def rset(self):
"""SMTP 'rset' command -- resets session."""
self.command_encoding = 'ascii'
return self.docmd("rset")
def _rset(self):
"""Internal 'rset' command which ignores any SMTPServerDisconnected error.
Used internally in the library, since the server disconnected error
should appear to the application when the *next* command is issued, if
we are doing an internal "safety" reset.
"""
try:
self.rset()
except SMTPServerDisconnected:
pass
def noop(self):
"""SMTP 'noop' command -- doesn't do anything :>"""
return self.docmd("noop")
def mail(self, sender, options=()):
"""SMTP 'mail' command -- begins mail xfer session.
This method may raise the following exceptions:
SMTPNotSupportedError The options parameter includes 'SMTPUTF8'
but the SMTPUTF8 extension is not supported by
the server.
"""
optionlist = ''
if options and self.does_esmtp:
if any(x.lower()=='smtputf8' for x in options):
if self.has_extn('smtputf8'):
self.command_encoding = 'utf-8'
else:
raise SMTPNotSupportedError(
'SMTPUTF8 not supported by server')
optionlist = ' ' + ' '.join(options)
self.putcmd("mail", "FROM:%s%s" % (quoteaddr(sender), optionlist))
return self.getreply()
def rcpt(self, recip, options=()):
"""SMTP 'rcpt' command -- indicates 1 recipient for this mail."""
optionlist = ''
if options and self.does_esmtp:
optionlist = ' ' + ' '.join(options)
self.putcmd("rcpt", "TO:%s%s" % (quoteaddr(recip), optionlist))
return self.getreply()
def data(self, msg):
"""SMTP 'DATA' command -- sends message data to server.
Automatically quotes lines beginning with a period per rfc821.
Raises SMTPDataError if there is an unexpected reply to the
DATA command; the return value from this method is the final
response code received when the all data is sent. If msg
is a string, lone '\\r' and '\\n' characters are converted to
'\\r\\n' characters. If msg is bytes, it is transmitted as is.
"""
self.putcmd("data")
(code, repl) = self.getreply()
if self.debuglevel > 0:
self._print_debug('data:', (code, repl))
if code != 354:
raise SMTPDataError(code, repl)
else:
if isinstance(msg, str):
msg = _fix_eols(msg).encode('ascii')
q = _quote_periods(msg)
if q[-2:] != bCRLF:
q = q + bCRLF
q = q + b"." + bCRLF
self.send(q)
(code, msg) = self.getreply()
if self.debuglevel > 0:
self._print_debug('data:', (code, msg))
return (code, msg)
def verify(self, address):
"""SMTP 'verify' command -- checks for address validity."""
self.putcmd("vrfy", _addr_only(address))
return self.getreply()
# a.k.a.
vrfy = verify
def expn(self, address):
"""SMTP 'expn' command -- expands a mailing list."""
self.putcmd("expn", _addr_only(address))
return self.getreply()
# some useful methods
def ehlo_or_helo_if_needed(self):
"""Call self.ehlo() and/or self.helo() if needed.
If there has been no previous EHLO or HELO command this session, this
method tries ESMTP EHLO first.
This method may raise the following exceptions:
SMTPHeloError The server didn't reply properly to
the helo greeting.
"""
if self.helo_resp is None and self.ehlo_resp is None:
if not (200 <= self.ehlo()[0] <= 299):
(code, resp) = self.helo()
if not (200 <= code <= 299):
raise SMTPHeloError(code, resp)
def auth(self, mechanism, authobject, *, initial_response_ok=True):
"""Authentication command - requires response processing.
'mechanism' specifies which authentication mechanism is to
be used - the valid values are those listed in the 'auth'
element of 'esmtp_features'.
'authobject' must be a callable object taking a single argument:
data = authobject(challenge)
It will be called to process the server's challenge response; the
challenge argument it is passed will be a bytes. It should return
an ASCII string that will be base64 encoded and sent to the server.
Keyword arguments:
- initial_response_ok: Allow sending the RFC 4954 initial-response
to the AUTH command, if the authentication methods supports it.
"""
# RFC 4954 allows auth methods to provide an initial response. Not all
# methods support it. By definition, if they return something other
# than None when challenge is None, then they do. See issue #15014.
mechanism = mechanism.upper()
initial_response = (authobject() if initial_response_ok else None)
if initial_response is not None:
response = encode_base64(initial_response.encode('ascii'), eol='')
(code, resp) = self.docmd("AUTH", mechanism + " " + response)
self._auth_challenge_count = 1
else:
(code, resp) = self.docmd("AUTH", mechanism)
self._auth_challenge_count = 0
# If server responds with a challenge, send the response.
while code == 334:
self._auth_challenge_count += 1
challenge = base64.decodebytes(resp)
response = encode_base64(
authobject(challenge).encode('ascii'), eol='')
(code, resp) = self.docmd(response)
# If server keeps sending challenges, something is wrong.
if self._auth_challenge_count > _MAXCHALLENGE:
raise SMTPException(
"Server AUTH mechanism infinite loop. Last response: "
+ repr((code, resp))
)
if code in (235, 503):
return (code, resp)
raise SMTPAuthenticationError(code, resp)
def auth_cram_md5(self, challenge=None):
""" Authobject to use with CRAM-MD5 authentication. Requires self.user
and self.password to be set."""
# CRAM-MD5 does not support initial-response.
if challenge is None:
return None
return self.user + " " + hmac.HMAC(
self.password.encode('ascii'), challenge, 'md5').hexdigest()
def auth_plain(self, challenge=None):
""" Authobject to use with PLAIN authentication. Requires self.user and
self.password to be set."""
return "\0%s\0%s" % (self.user, self.password)
def auth_login(self, challenge=None):
""" Authobject to use with LOGIN authentication. Requires self.user and
self.password to be set."""
if challenge is None or self._auth_challenge_count < 2:
return self.user
else:
return self.password
def login(self, user, password, *, initial_response_ok=True):
"""Log in on an SMTP server that requires authentication.
The arguments are:
- user: The user name to authenticate with.
- password: The password for the authentication.
Keyword arguments:
- initial_response_ok: Allow sending the RFC 4954 initial-response
to the AUTH command, if the authentication methods supports it.
If there has been no previous EHLO or HELO command this session, this
method tries ESMTP EHLO first.
This method will return normally if the authentication was successful.
This method 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.
"""
self.ehlo_or_helo_if_needed()
if not self.has_extn("auth"):
raise SMTPNotSupportedError(
"SMTP AUTH extension not supported by server.")
# Authentication methods the server claims to support
advertised_authlist = self.esmtp_features["auth"].split()
# Authentication methods we can handle in our preferred order:
preferred_auths = ['CRAM-MD5', 'PLAIN', 'LOGIN']
# We try the supported authentications in our preferred order, if
# the server supports them.
authlist = [auth for auth in preferred_auths
if auth in advertised_authlist]
if not authlist:
raise SMTPException("No suitable authentication method found.")
# Some servers advertise authentication methods they don't really
# support, so if authentication fails, we continue until we've tried
# all methods.
self.user, self.password = user, password
for authmethod in authlist:
method_name = 'auth_' + authmethod.lower().replace('-', '_')
try:
(code, resp) = self.auth(
authmethod, getattr(self, method_name),
initial_response_ok=initial_response_ok)
# 235 == 'Authentication successful'
# 503 == 'Error: already authenticated'
if code in (235, 503):
return (code, resp)
except SMTPAuthenticationError as e:
last_exception = e
# We could not login successfully. Return result of last attempt.
raise last_exception
def starttls(self, keyfile=None, certfile=None, context=None):
"""Puts the connection to the SMTP server into TLS mode.
If there has been no previous EHLO or HELO command this session, this
method tries ESMTP EHLO first.
If the server supports TLS, this will encrypt the rest of the SMTP
session. If you provide the keyfile and certfile parameters,
the identity of the SMTP server and client can be checked. This,
however, depends on whether the socket module really checks the
certificates.
This method may raise the following exceptions:
SMTPHeloError The server didn't reply properly to
the helo greeting.
"""
self.ehlo_or_helo_if_needed()
if not self.has_extn("starttls"):
raise SMTPNotSupportedError(
"STARTTLS extension not supported by server.")
(resp, reply) = self.docmd("STARTTLS")
if resp == 220:
if not _have_ssl:
raise RuntimeError("No SSL support included in this Python")
if context is not None and keyfile is not None:
raise ValueError("context and keyfile arguments are mutually "
"exclusive")
if context is not None and certfile is not None:
raise ValueError("context and certfile arguments are mutually "
"exclusive")
if keyfile is not None or certfile is not None:
import warnings
warnings.warn("keyfile and certfile are deprecated, use a "
"custom context instead", DeprecationWarning, 2)
if context is None:
context = ssl._create_stdlib_context(certfile=certfile,
keyfile=keyfile)
self.sock = context.wrap_socket(self.sock,
server_hostname=self._host)
self.file = None
# RFC 3207:
# The client MUST discard any knowledge obtained from
# the server, such as the list of SMTP service extensions,
# which was not obtained from the TLS negotiation itself.
self.helo_resp = None
self.ehlo_resp = None
self.esmtp_features = {}
self.does_esmtp = 0
else:
# RFC 3207:
# 501 Syntax error (no parameters allowed)
# 454 TLS not available due to temporary reason
raise SMTPResponseException(resp, reply)
return (resp, reply)
def sendmail(self, from_addr, to_addrs, msg, mail_options=(),
rcpt_options=()):
"""This command performs an entire mail transaction.
The arguments are:
- from_addr : The address sending this mail.
- to_addrs : A list of addresses to send this mail to. A bare
string will be treated as a list with 1 address.
- msg : The message to send.
- mail_options : List of ESMTP options (such as 8bitmime) for the
mail command.
- rcpt_options : List of ESMTP options (such as DSN commands) for
all the rcpt commands.
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.
If there has been no previous EHLO or HELO command this session, this
method tries ESMTP EHLO first. If the server does ESMTP, message size
and each of the specified options will be passed to it. If EHLO
fails, HELO will be tried and ESMTP options suppressed.
This method will return normally if the mail is accepted for at least
one recipient. 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.
This method may raise the following exceptions:
SMTPHeloError The server didn't reply properly to
the helo greeting.
SMTPRecipientsRefused The server rejected ALL recipients
(no mail was sent).
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 The mail_options parameter includes 'SMTPUTF8'
but the SMTPUTF8 extension is not supported by
the server.
Note: the connection will be open even after an exception is raised.
Example:
>>> import smtplib
>>> s=smtplib.SMTP("localhost")
>>> tolist=["one@one.org","two@two.org","three@three.org","four@four.org"]
>>> msg = '''\\
... From: Me@my.org
... Subject: testin'...
...
... This is a test '''
>>> s.sendmail("me@my.org",tolist,msg)
{ "three@three.org" : ( 550 ,"User unknown" ) }
>>> s.quit()
In the above example, the message was accepted for delivery to three
of the four addresses, and one was rejected, with the error code
550. If all addresses are accepted, then the method will return an
empty dictionary.
"""
self.ehlo_or_helo_if_needed()
esmtp_opts = []
if isinstance(msg, str):
msg = _fix_eols(msg).encode('ascii')
if self.does_esmtp:
if self.has_extn('size'):
esmtp_opts.append("size=%d" % len(msg))
for option in mail_options:
esmtp_opts.append(option)
(code, resp) = self.mail(from_addr, esmtp_opts)
if code != 250:
if code == 421:
self.close()
else:
self._rset()
raise SMTPSenderRefused(code, resp, from_addr)
senderrs = {}
if isinstance(to_addrs, str):
to_addrs = [to_addrs]
for each in to_addrs:
(code, resp) = self.rcpt(each, rcpt_options)
if (code != 250) and (code != 251):
senderrs[each] = (code, resp)
if code == 421:
self.close()
raise SMTPRecipientsRefused(senderrs)
if len(senderrs) == len(to_addrs):
# the server refused all our recipients
self._rset()
raise SMTPRecipientsRefused(senderrs)
(code, resp) = self.data(msg)
if code != 250:
if code == 421:
self.close()
else:
self._rset()
raise SMTPDataError(code, resp)
#if we got here then somebody got our mail
return senderrs
def send_message(self, msg, from_addr=None, to_addrs=None,
mail_options=(), rcpt_options=()):
"""Converts message to a bytestring and passes it to sendmail.
The arguments are as for sendmail, except that msg is an
email.message.Message object. If from_addr is None or to_addrs is
None, these arguments are taken from the headers of the Message as
described in RFC 2822 (a ValueError is raised if there is more than
one set of 'Resent-' headers). Regardless of the values of from_addr and
to_addr, any Bcc field (or Resent-Bcc field, when the Message is a
resent) of the Message object won't be transmitted. The Message
object is then serialized using email.generator.BytesGenerator and
sendmail is called to transmit the message. If the sender or any of
the recipient addresses contain non-ASCII and the server advertises the
SMTPUTF8 capability, the policy is cloned with utf8 set to True for the
serialization, and SMTPUTF8 and BODY=8BITMIME are asserted on the send.
If the server does not support SMTPUTF8, an SMTPNotSupported error is
raised. Otherwise the generator is called without modifying the
policy.
"""
# 'Resent-Date' is a mandatory field if the Message is resent (RFC 2822
# Section 3.6.6). In such a case, we use the 'Resent-*' fields. However,
# if there is more than one 'Resent-' block there's no way to
# unambiguously determine which one is the most recent in all cases,
# so rather than guess we raise a ValueError in that case.
#
# TODO implement heuristics to guess the correct Resent-* block with an
# option allowing the user to enable the heuristics. (It should be
# possible to guess correctly almost all of the time.)
self.ehlo_or_helo_if_needed()
resent = msg.get_all('Resent-Date')
if resent is None:
header_prefix = ''
elif len(resent) == 1:
header_prefix = 'Resent-'
else:
raise ValueError("message has more than one 'Resent-' header block")
if from_addr is None:
# Prefer the sender field per RFC 2822:3.6.2.
from_addr = (msg[header_prefix + 'Sender']
if (header_prefix + 'Sender') in msg
else msg[header_prefix + 'From'])
from_addr = email.utils.getaddresses([from_addr])[0][1]
if to_addrs is None:
addr_fields = [f for f in (msg[header_prefix + 'To'],
msg[header_prefix + 'Bcc'],
msg[header_prefix + 'Cc'])
if f is not None]
to_addrs = [a[1] for a in email.utils.getaddresses(addr_fields)]
# Make a local copy so we can delete the bcc headers.
msg_copy = copy.copy(msg)
del msg_copy['Bcc']
del msg_copy['Resent-Bcc']
international = False
try:
''.join([from_addr, *to_addrs]).encode('ascii')
except UnicodeEncodeError:
if not self.has_extn('smtputf8'):
raise SMTPNotSupportedError(
"One or more source or delivery addresses require"
" internationalized email support, but the server"
" does not advertise the required SMTPUTF8 capability")
international = True
with io.BytesIO() as bytesmsg:
if international:
g = email.generator.BytesGenerator(
bytesmsg, policy=msg.policy.clone(utf8=True))
mail_options = (*mail_options, 'SMTPUTF8', 'BODY=8BITMIME')
else:
g = email.generator.BytesGenerator(bytesmsg)
g.flatten(msg_copy, linesep='\r\n')
flatmsg = bytesmsg.getvalue()
return self.sendmail(from_addr, to_addrs, flatmsg, mail_options,
rcpt_options)
def close(self):
"""Close the connection to the SMTP server."""
try:
file = self.file
self.file = None
if file:
file.close()
finally:
sock = self.sock
self.sock = None
if sock:
sock.close()
def quit(self):
"""Terminate the SMTP session."""
res = self.docmd("quit")
# A new EHLO is required after reconnecting with connect()
self.ehlo_resp = self.helo_resp = None
self.esmtp_features = {}
self.does_esmtp = False
self.close()
return res
if _have_ssl:
class SMTP_SSL(SMTP):
""" This is a subclass derived from SMTP that connects over an SSL
encrypted socket (to use this class you need a socket module that was
compiled with SSL support). If host is not specified, '' (the local
host) is used. If port is omitted, the standard SMTP-over-SSL port
(465) is used. local_hostname and source_address have the same meaning
as they do in the SMTP class. keyfile and certfile are also optional -
they can contain a PEM formatted private key and certificate chain file
for the SSL connection. context also optional, can contain a
SSLContext, and is an alternative to keyfile and certfile; If it is
specified both keyfile and certfile must be None.
"""
default_port = SMTP_SSL_PORT
def __init__(self, host='', port=0, local_hostname=None,
keyfile=None, certfile=None,
timeout=socket._GLOBAL_DEFAULT_TIMEOUT,
source_address=None, context=None):
if context is not None and keyfile is not None:
raise ValueError("context and keyfile arguments are mutually "
"exclusive")
if context is not None and certfile is not None:
raise ValueError("context and certfile arguments are mutually "
"exclusive")
if keyfile is not None or certfile is not None:
import warnings
warnings.warn("keyfile and certfile are deprecated, use a "
"custom context instead", DeprecationWarning, 2)
self.keyfile = keyfile
self.certfile = certfile
if context is None:
context = ssl._create_stdlib_context(certfile=certfile,
keyfile=keyfile)
self.context = context
SMTP.__init__(self, host, port, local_hostname, timeout,
source_address)
def _get_socket(self, host, port, timeout):
if self.debuglevel > 0:
self._print_debug('connect:', (host, port))
new_socket = super()._get_socket(host, port, timeout)
new_socket = self.context.wrap_socket(new_socket,
server_hostname=self._host)
return new_socket
__all__.append("SMTP_SSL")
#
# LMTP extension
#
LMTP_PORT = 2003
class LMTP(SMTP):
"""LMTP - Local Mail Transfer Protocol
The LMTP protocol, which is very similar to ESMTP, is heavily based
on the standard SMTP client. It's common to use Unix sockets for
LMTP, so our connect() method must support that as well as a regular
host:port server. local_hostname and source_address have the same
meaning as they do in the SMTP class. To specify a Unix socket,
you must use an absolute path as the host, starting with a '/'.
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."""
ehlo_msg = "lhlo"
def __init__(self, host='', port=LMTP_PORT, local_hostname=None,
source_address=None, timeout=socket._GLOBAL_DEFAULT_TIMEOUT):
"""Initialize a new instance."""
super().__init__(host, port, local_hostname=local_hostname,
source_address=source_address, timeout=timeout)
def connect(self, host='localhost', port=0, source_address=None):
"""Connect to the LMTP daemon, on either a Unix or a TCP socket."""
if host[0] != '/':
return super().connect(host, port, source_address=source_address)
if self.timeout is not None and not self.timeout:
raise ValueError('Non-blocking socket (timeout=0) is not supported')
# Handle Unix-domain sockets.
try:
self.sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
if self.timeout is not socket._GLOBAL_DEFAULT_TIMEOUT:
self.sock.settimeout(self.timeout)
self.file = None
self.sock.connect(host)
except OSError:
if self.debuglevel > 0:
self._print_debug('connect fail:', host)
if self.sock:
self.sock.close()
self.sock = None
raise
(code, msg) = self.getreply()
if self.debuglevel > 0:
self._print_debug('connect:', msg)
return (code, msg)
# Test the sendmail method, which tests most of the others.
# Note: This always sends to localhost.
if __name__ == '__main__':
def prompt(prompt):
sys.stdout.write(prompt + ": ")
sys.stdout.flush()
return sys.stdin.readline().strip()
fromaddr = prompt("From")
toaddrs = prompt("To").split(',')
print("Enter message, end with ^D:")
msg = ''
while 1:
line = sys.stdin.readline()
if not line:
break
msg = msg + line
print("Message length is %d" % len(msg))
server = SMTP('localhost')
server.set_debuglevel(1)
server.sendmail(fromaddr, toaddrs, msg)
server.quit()
