python写的一个邮件收发工具

import smtplib
import mimetypes
import os
from email import encoders
from email.header import Header
from email.message import Message
from email.mime.audio import MIMEAudio
from email.mime.base import MIMEBase
from email.mime.image import MIMEImage
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText


CONTENT_ENCODING = 'UTF-8'
COMMASPACE = ','


def _header(s):
    if type(s) == str:
        return s
    elif type(s) == unicode:
        return Header(s.encode(CONTENT_ENCODING), CONTENT_ENCODING).encode()


class MailSender(object):
    def __init__(self, smtp_host, username, password,
                 verify_ssl, default_sender, timeout=30.0):
        self.set_smtp(smtp_host, username, password, verify_ssl)
        self.default_sender = default_sender
        self.timeout = timeout

    def set_smtp(self, smtp_host, username, password, verify_ssl):
        self.smtp_host = smtp_host
        self.username = username
        self.password = password
        self.verify_ssl = verify_ssl

    def sendmail(self, to_list, subject, text, cc_list=[],
                 file_paths=[], bcc_list=[], sender=None):
        if not sender:
            sender = self.default_sender
        msg = self.compose_msg(to_list, subject, text,
                               cc_list, file_paths, sender)
        to_addrs = to_list + cc_list + bcc_list
        server = smtplib.SMTP(self.smtp_host, timeout=self.timeout)
        if self.verify_ssl:
            server.ehlo()
            server.starttls()
            server.ehlo()
        else:
            server.ehlo()
        if self.username:
            server.login(self.username, self.password)
        server.sendmail(sender, to_addrs, msg)
        server.quit()

    def compose_msg(self, to_list, subject, text, cc_list=[],
                    file_paths=[], sender=None):
        if not sender:
            sender = self.default_sender

        outer = MIMEMultipart()
        outer['Subject'] = _header(subject)
        outer['To'] = COMMASPACE.join(to_list)
        if cc_list:
            outer['CC'] = COMMASPACE.join(cc_list)
        outer['From'] = sender

        if type(text) == unicode:
            textpart = MIMEText(text.encode(CONTENT_ENCODING),
                                'plain', CONTENT_ENCODING)
        else:
            textpart = MIMEText(str(text), 'plain', CONTENT_ENCODING)
        outer.attach(textpart)

        for path in file_paths:
            file_name = os.path.basename(path)
            ctype, encoding = mimetypes.guess_type(path)
            if ctype is None or encoding is not None:
                ctype = 'application/octet-stream'
            maintype, subtype = ctype.split('/', 1)
            fp = open(path, 'rb')
            data = fp.read()
            fp.close()
            if maintype == 'text':
                msg = MIMEText(data, _subtype=subtype)
            elif maintype == 'image':
                msg = MIMEImage(data, _subtype=subtype)
            elif maintype == 'audio':
                msg = MIMEAudio(data, _subtype=subtype)
            else:
                msg = MIMEBase(maintype, subtype)
                msg.set_payload(data)
                encoders.encode_base64(msg)
            if type(file_name) == unicode:
                #s_filename = ('utf-8', '', file_name.encode(CONTENT_ENCODING))
                s_filename = file_name.encode(CONTENT_ENCODING)
            else:
                s_filename = str(file_name)
            msg.add_header('Content-Disposition',
                           'attachment', filename=s_filename)
            outer.attach(msg)

        return outer.as_string()