blob: a3213b33d715e54e42fec490d79759568b36501a [file] [log] [blame]
#! /usr/bin/env python
'''SMTP/ESMTP client class.
This should follow RFC 821 (SMTP), RFC 1869 (ESMTP), RFC 2554 (SMTP
Authentication) and RFC 2487 (Secure SMTP over TLS).
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!
>>> import smtplib
>>> s=smtplib.SMTP("localhost")
>>> print
This is Sendmail version 8.8.4
For more info use "HELP <topic>".
To report bugs in the implementation send email to
For local information send email to Postmaster at your site.
End of HELP info
>>> s.putcmd("vrfy","someone@here")
>>> s.getreply()
(250, "Somebody OverHere <>")
>>> s.quit()
# Author: The Dragon De Monsyne <>
# ESMTP support, test code and doc fixes added by
# Eric S. Raymond <>
# Better RFC 821 compliance (MAIL and RCPT, and CRLF in data)
# by Carey Evans <>, for picky mail servers.
# RFC 2554 (authentication) support by Gerhard Haering <>.
# This was modified from the Python 1.5 library HTTP lib.
import socket
import re
import email.utils
import base64
import hmac
from email.base64mime import encode as encode_base64
from sys import stderr
__all__ = ["SMTPException", "SMTPServerDisconnected", "SMTPResponseException",
"SMTPSenderRefused", "SMTPRecipientsRefused", "SMTPDataError",
"SMTPConnectError", "SMTPHeloError", "SMTPAuthenticationError",
"quoteaddr", "quotedata", "SMTP"]
CRLF = "\r\n"
OLDSTYLE_AUTH = re.compile(r"auth=(.*)", re.I)
# Exception classes used by this module.
class SMTPException(Exception):
"""Base class for all exceptions raised by this module."""
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(addr):
"""Quote a subset of the email addresses defined by RFC 821.
Should be able to handle anything rfc822.parseaddr can handle.
m = (None, None)
m = email.utils.parseaddr(addr)[1]
except AttributeError:
if m == (None, None): # Indicates parse failure or AttributeError
# something weird here.. punt -ddm
return "<%s>" % addr
elif m is None:
# the sender wants an empty return address
return "<>"
return "<%s>" % m
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
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))
import ssl
except ImportError:
_have_ssl = False
class SSLFakeFile:
"""A fake file like object that really wraps a SSLObject.
It only supports what is needed in smtplib.
def __init__(self, sslobj):
self.sslobj = sslobj
def readline(self):
str = ""
chr = None
while chr != "\n":
chr =
if not chr:
str += chr
return str
def close(self):
_have_ssl = True
class SMTP:
"""This class manages a connection to an SMTP or ESMTP server.
SMTP Objects:
SMTP objects have the following attributes:
This is the message given by the server in response to the
most recent HELO command.
This is the message given by the server in response to the
most recent EHLO command. This is usually multiline.
This is a True value _after you do an EHLO command_, if the
server supports ESMTP.
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
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
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,
"""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. By default,
the local hostname is found using socket.getfqdn().
self.timeout = timeout
self.esmtp_features = {}
if host:
(code, msg) = self.connect(host, port)
if code != 220:
raise SMTPConnectError(code, msg)
if local_hostname is not None:
self.local_hostname = local_hostname
# 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
# We can't find an fqdn hostname, so use a domain literal
addr = ''
addr = socket.gethostbyname(socket.gethostname())
except socket.gaierror:
self.local_hostname = '[%s]' % addr
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 _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 self.debuglevel > 0:
print>>stderr, 'connect:', (host, port)
return socket.create_connection((host, port), timeout)
def connect(self, host='localhost', port=0):
"""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 not port and (host.find(':') == host.rfind(':')):
i = host.rfind(':')
if i >= 0:
host, port = host[:i], host[i + 1:]
port = int(port)
except ValueError:
raise socket.error, "nonnumeric port"
if not port:
port = self.default_port
if self.debuglevel > 0:
print>>stderr, 'connect:', (host, port)
self.sock = self._get_socket(host, port, self.timeout)
(code, msg) = self.getreply()
if self.debuglevel > 0:
print>>stderr, "connect:", msg
return (code, msg)
def send(self, str):
"""Send `str' to the server."""
if self.debuglevel > 0:
print>>stderr, 'send:', repr(str)
if hasattr(self, 'sock') and self.sock:
except socket.error:
raise SMTPServerDisconnected('Server not connected')
raise SMTPServerDisconnected('please run connect() first')
def putcmd(self, cmd, args=""):
"""Send a command to the server."""
if args == "":
str = '%s%s' % (cmd, CRLF)
str = '%s %s%s' % (cmd, args, 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:
line = self.file.readline()
except socket.error as e:
raise SMTPServerDisconnected("Connection unexpectedly closed: "
+ str(e))
if line == '':
raise SMTPServerDisconnected("Connection unexpectedly closed")
if self.debuglevel > 0:
print>>stderr, 'reply:', repr(line)
code = line[:3]
# Check that the error code is syntactically correct.
# Don't attempt to read a continuation line if it is broken.
errcode = int(code)
except ValueError:
errcode = -1
# Check if multiline response.
if line[3:4] != "-":
errmsg = "\n".join(resp)
if self.debuglevel > 0:
print>>stderr, 'reply: retcode (%s); Msg: %s' % (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
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
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:
raise SMTPServerDisconnected("Server not connected")
self.ehlo_resp = msg
if code != 250:
return (code, msg)
self.does_esmtp = 1
#parse the ehlo response -ddm
resp = self.ehlo_resp.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]
# 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 ="feature").lower()
params = m.string[m.end("feature"):].strip()
if feature == "auth":
self.esmtp_features[feature] = self.esmtp_features.get(feature, "") \
+ " " + params
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."""
return self.docmd("rset")
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."""
optionlist = ''
if options and self.does_esmtp:
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.
(code, repl) = self.getreply()
if self.debuglevel > 0:
print>>stderr, "data:", (code, repl)
if code != 354:
raise SMTPDataError(code, repl)
q = quotedata(msg)
if q[-2:] != CRLF:
q = q + CRLF
q = q + "." + CRLF
(code, msg) = self.getreply()
if self.debuglevel > 0:
print>>stderr, "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 login(self, user, password):
"""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.
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.
SMTPException No suitable authentication method was
def encode_cram_md5(challenge, user, password):
challenge = base64.decodestring(challenge)
response = user + " " + hmac.HMAC(password, challenge).hexdigest()
return encode_base64(response, eol="")
def encode_plain(user, password):
return encode_base64("\0%s\0%s" % (user, password), eol="")
if not self.has_extn("auth"):
raise SMTPException("SMTP AUTH extension not supported by server.")
# Authentication methods the server supports:
authlist = self.esmtp_features["auth"].split()
# List of authentication methods we support: from preferred to
# less preferred methods. Except for the purpose of testing the weaker
# ones, we prefer stronger methods like CRAM-MD5:
preferred_auths = [AUTH_CRAM_MD5, AUTH_PLAIN, AUTH_LOGIN]
# Determine the authentication method we'll use
authmethod = None
for method in preferred_auths:
if method in authlist:
authmethod = method
if authmethod == AUTH_CRAM_MD5:
(code, resp) = self.docmd("AUTH", AUTH_CRAM_MD5)
if code == 503:
# 503 == 'Error: already authenticated'
return (code, resp)
(code, resp) = self.docmd(encode_cram_md5(resp, user, password))
elif authmethod == AUTH_PLAIN:
(code, resp) = self.docmd("AUTH",
AUTH_PLAIN + " " + encode_plain(user, password))
elif authmethod == AUTH_LOGIN:
(code, resp) = self.docmd("AUTH",
"%s %s" % (AUTH_LOGIN, encode_base64(user, eol="")))
if code != 334:
raise SMTPAuthenticationError(code, resp)
(code, resp) = self.docmd(encode_base64(password, eol=""))
elif authmethod is None:
raise SMTPException("No suitable authentication method found.")
if code not in (235, 503):
# 235 == 'Authentication successful'
# 503 == 'Error: already authenticated'
raise SMTPAuthenticationError(code, resp)
return (code, resp)
def starttls(self, keyfile=None, certfile=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
This method may raise the following exceptions:
SMTPHeloError The server didn't reply properly to
the helo greeting.
if not self.has_extn("starttls"):
raise SMTPException("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")
self.sock = ssl.wrap_socket(self.sock, keyfile, certfile)
self.file = SSLFakeFile(self.sock)
# 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
return (resp, reply)
def sendmail(self, from_addr, to_addrs, msg, mail_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.
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).
Note: the connection will be open even after an exception is raised.
>>> import smtplib
>>> s=smtplib.SMTP("localhost")
>>> tolist=["","","",""]
>>> msg = '''\\
... From:
... Subject: testin'...
... This is a test '''
>>> s.sendmail("",tolist,msg)
{ "" : ( 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.
esmtp_opts = []
if self.does_esmtp:
# Hmmm? what's this? -ddm
# self.esmtp_features['7bit']=""
if self.has_extn('size'):
esmtp_opts.append("size=%d" % len(msg))
for option in mail_options:
(code, resp) = self.mail(from_addr, esmtp_opts)
if code != 250:
raise SMTPSenderRefused(code, resp, from_addr)
senderrs = {}
if isinstance(to_addrs, basestring):
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 len(senderrs) == len(to_addrs):
# the server refused all our recipients
raise SMTPRecipientsRefused(senderrs)
(code, resp) =
if code != 250:
raise SMTPDataError(code, resp)
#if we got here then somebody got our mail
return senderrs
def close(self):
"""Close the connection to the SMTP server."""
if self.file:
self.file = None
if self.sock:
self.sock = None
def quit(self):
"""Terminate the SMTP session."""
res = self.docmd("quit")
return res
if _have_ssl:
""" 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. keyfile and certfile
are also optional - they can contain a PEM formatted private key and
certificate chain file for the SSL connection.
default_port = SMTP_SSL_PORT
def __init__(self, host='', port=0, local_hostname=None,
keyfile=None, certfile=None,
self.keyfile = keyfile
self.certfile = certfile
SMTP.__init__(self, host, port, local_hostname, timeout)
def _get_socket(self, host, port, timeout):
if self.debuglevel > 0:
print>>stderr, 'connect:', (host, port)
new_socket = socket.create_connection((host, port), timeout)
new_socket = ssl.wrap_socket(new_socket, self.keyfile, self.certfile)
self.file = SSLFakeFile(new_socket)
return new_socket
# 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. 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):
"""Initialize a new instance."""
SMTP.__init__(self, host, port, local_hostname)
def connect(self, host='localhost', port=0):
"""Connect to the LMTP daemon, on either a Unix or a TCP socket."""
if host[0] != '/':
return SMTP.connect(self, host, port)
# Handle Unix-domain sockets.
self.sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
except socket.error:
if self.debuglevel > 0:
print>>stderr, 'connect fail:', host
if self.sock:
self.sock = None
(code, msg) = self.getreply()
if self.debuglevel > 0:
print>>stderr, "connect:", msg
return (code, msg)
# Test the sendmail method, which tests most of the others.
# Note: This always sends to localhost.
if __name__ == '__main__':
import sys
def prompt(prompt):
sys.stdout.write(prompt + ": ")
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:
msg = msg + line
print "Message length is %d" % len(msg)
server = SMTP('localhost')
server.sendmail(fromaddr, toaddrs, msg)