"""
Mail sending helpers
See documentation in docs/topics/email.rst
"""
import logging
from email import encoders as Encoders
from email.mime.base import MIMEBase
from email.mime.multipart import MIMEMultipart
from email.mime.nonmultipart import MIMENonMultipart
from email.mime.text import MIMEText
from email.utils import formatdate
from io import BytesIO
from twisted import version as twisted_version
from twisted.internet import defer, ssl
from twisted.python.versions import Version
from scrapy.utils.misc import arg_to_iter
from scrapy.utils.python import to_bytes
logger = logging.getLogger(__name__)
# Defined in the email.utils module, but undocumented:
# https://github.com/python/cpython/blob/v3.9.0/Lib/email/utils.py#L42
COMMASPACE = ", "
def _to_bytes_or_none(text):
if text is None:
return None
return to_bytes(text)
[docs]class MailSender:
def __init__(
self,
smtphost="localhost",
mailfrom="scrapy@localhost",
smtpuser=None,
smtppass=None,
smtpport=25,
smtptls=False,
smtpssl=False,
debug=False,
):
self.smtphost = smtphost
self.smtpport = smtpport
self.smtpuser = _to_bytes_or_none(smtpuser)
self.smtppass = _to_bytes_or_none(smtppass)
self.smtptls = smtptls
self.smtpssl = smtpssl
self.mailfrom = mailfrom
self.debug = debug
[docs] @classmethod
def from_settings(cls, settings):
return cls(
smtphost=settings["MAIL_HOST"],
mailfrom=settings["MAIL_FROM"],
smtpuser=settings["MAIL_USER"],
smtppass=settings["MAIL_PASS"],
smtpport=settings.getint("MAIL_PORT"),
smtptls=settings.getbool("MAIL_TLS"),
smtpssl=settings.getbool("MAIL_SSL"),
)
[docs] def send(
self,
to,
subject,
body,
cc=None,
attachs=(),
mimetype="text/plain",
charset=None,
_callback=None,
):
from twisted.internet import reactor
if attachs:
msg = MIMEMultipart()
else:
msg = MIMENonMultipart(*mimetype.split("/", 1))
to = list(arg_to_iter(to))
cc = list(arg_to_iter(cc))
msg["From"] = self.mailfrom
msg["To"] = COMMASPACE.join(to)
msg["Date"] = formatdate(localtime=True)
msg["Subject"] = subject
rcpts = to[:]
if cc:
rcpts.extend(cc)
msg["Cc"] = COMMASPACE.join(cc)
if charset:
msg.set_charset(charset)
if attachs:
msg.attach(MIMEText(body, "plain", charset or "us-ascii"))
for attach_name, mimetype, f in attachs:
part = MIMEBase(*mimetype.split("/"))
part.set_payload(f.read())
Encoders.encode_base64(part)
part.add_header(
"Content-Disposition", "attachment", filename=attach_name
)
msg.attach(part)
else:
msg.set_payload(body)
if _callback:
_callback(to=to, subject=subject, body=body, cc=cc, attach=attachs, msg=msg)
if self.debug:
logger.debug(
"Debug mail sent OK: To=%(mailto)s Cc=%(mailcc)s "
'Subject="%(mailsubject)s" Attachs=%(mailattachs)d',
{
"mailto": to,
"mailcc": cc,
"mailsubject": subject,
"mailattachs": len(attachs),
},
)
return
dfd = self._sendmail(rcpts, msg.as_string().encode(charset or "utf-8"))
dfd.addCallbacks(
callback=self._sent_ok,
errback=self._sent_failed,
callbackArgs=[to, cc, subject, len(attachs)],
errbackArgs=[to, cc, subject, len(attachs)],
)
reactor.addSystemEventTrigger("before", "shutdown", lambda: dfd)
return dfd
def _sent_ok(self, result, to, cc, subject, nattachs):
logger.info(
"Mail sent OK: To=%(mailto)s Cc=%(mailcc)s "
'Subject="%(mailsubject)s" Attachs=%(mailattachs)d',
{
"mailto": to,
"mailcc": cc,
"mailsubject": subject,
"mailattachs": nattachs,
},
)
def _sent_failed(self, failure, to, cc, subject, nattachs):
errstr = str(failure.value)
logger.error(
"Unable to send mail: To=%(mailto)s Cc=%(mailcc)s "
'Subject="%(mailsubject)s" Attachs=%(mailattachs)d'
"- %(mailerr)s",
{
"mailto": to,
"mailcc": cc,
"mailsubject": subject,
"mailattachs": nattachs,
"mailerr": errstr,
},
)
def _sendmail(self, to_addrs, msg):
from twisted.internet import reactor
msg = BytesIO(msg)
d = defer.Deferred()
factory = self._create_sender_factory(to_addrs, msg, d)
if self.smtpssl:
reactor.connectSSL(
self.smtphost, self.smtpport, factory, ssl.ClientContextFactory()
)
else:
reactor.connectTCP(self.smtphost, self.smtpport, factory)
return d
def _create_sender_factory(self, to_addrs, msg, d):
from twisted.mail.smtp import ESMTPSenderFactory
factory_keywords = {
"heloFallback": True,
"requireAuthentication": False,
"requireTransportSecurity": self.smtptls,
}
# Newer versions of twisted require the hostname to use STARTTLS
if twisted_version >= Version("twisted", 21, 2, 0):
factory_keywords["hostname"] = self.smtphost
factory = ESMTPSenderFactory(
self.smtpuser,
self.smtppass,
self.mailfrom,
to_addrs,
msg,
d,
**factory_keywords
)
factory.noisy = False
return factory