由於工作中經常需要收發電子郵件，例如每日（周）的工作報告，測試報告，監控告警，定時提醒等等，大都已電子郵件的形式傳送。本文將實現一個 Python 的電子郵件傳送類，支援傳送多個附件（目錄），HTML或純文字內容，抄送收件人，多個接收者等功能。

程式碼實現

#!/usr/bin/env python
# -*- coding: utf-8 -*-
'''
Copyright (C)  2015 By Thomas Hu.  All rights reserved.
@author : Thomas Hu
@version: 1.0
@created: 2015-05-17
'''
import base64
import httplib
import re
import os
import smtplib
from xml.etree import ElementTree
from email.utils import formatdate
from email.MIMEText import MIMEText
from email.MIMEBase import MIMEBase
from email.MIMEMultipart import MIMEMultipart
from email import Encoders

class EmailSender(object):
    def __init__(self, smtp_server, smtp_port=0, verbose=False, debug_level=1, encoding="utf-8"):
        ''' Initiate the EmailSender.
        @param smtp_server: the Email SMTP server.
        @param smtp_port:   the Email SMTP server port, if use the default port(25), you can set it to 0 or 25.
        @param verbose:     show the processing information if set to 'True', default is 'False'.
        @param debug_level: set the smtplib debug level, if it's '0', will enable debug information.
        @param encoding:    the encoding or charset for email body text or attachment file name, default is "utf-8".
        '''
        self.server = smtp_server
        self.port = int(smtp_port)
        self.verbose = verbose
        self.debug_level = int(debug_level)
        self.encoding = encoding
        self.attachments = []

        #Create smtp instance
        self.smtp = smtplib.SMTP(self.server, self.port)
        self.smtp.set_debuglevel(self.debug_level)
        self.print_verbose("Init SMTP server successfully. server=%s, port=%d."%(self.server, self.port))

    def print_verbose(self, message):
        '''Print the verbose information.
        @param message: the message to be print if the verbose is "True".
        '''
        if self.verbose:
            print(message)
            
    def login(self, user, password):
        '''Login to SMTP server.
        @param user:     the user name of the email sender.
        @param password: the passord of the user for login to SMTP server.
        '''
        self.from_addr = user + "@" + ".".join(self.server.split(".")[1:])
        try:
            self.print_verbose("Start to login into SMTP server.server=%s, port=%d."%(self.server, self.port))
            self.smtp.login(user, password)
            self.print_verbose("Login into SMTP server successfully.")
        except Exception as ex:
            print("Login into SMTP server failed! Error info: %s"%(str(ex)))

    def __add_attachment_file(self, filename, encoding, Filter):
        '''Add attachment file to the attachment list.
        @param filename:  the file name of attachment, should not be a path.
        @param encoding:  the encode of the attachment file name.
        @param Filter:    the file filter object, must implement 'accept(filename)' interface, and return True or False.
        '''
        # Check if the file is acceptable by the Filter
        if Filter is not None:
            try:
                accept = Filter.accept(filename)
            except:
                accept = False
            if accept == False:
                return
        # Add the attachment to the attachment list
        try:
            basename = os.path.basename(filename)
            attach = MIMEBase("application", "octet-stream")
            attach.set_payload(open(filename, "rb").read())
            #attach.add_header("Content-Disposition", "attachment;filename=%s"%(basename))
            attach.add_header("Content-Disposition", "attachment", filename=(encoding, "", basename))
            Encoders.encode_base64(attach)
            self.attachments.append(attach)
            self.print_verbose("Add attachment \"%s\" successfully."%(filename))
        except Exception as ex:
            print("Add attachment file \"%s\" failed. Error info: %s."%(filename, str(ex)))
                
    def add_attachment(self, path, encoding=None, Filter=None):
        '''Add attachment file to the attachment list.
        @param path:      the path of files to be added as attachment files. If is a directory, all of the files in it will be added.
        @param encoding:  the encode of the attachment file name.
        @param Filter:    the file filter object, must implement 'accept(filename)' interface, and return True or False.
        '''
        if not os.path.exists(path):
            self.print_verbose("Warning: attachment path \"%s\" is not exists."%(path))
            return
        charset = encoding if (encoding is not None) else self.encoding
        if os.path.isfile(path):
            return self.__add_attachment_file(path, charset, Filter)
        for root, dirs, files in os.walk(path):
            for f in files:
                fname = os.path.join(root, f)
                self.__add_attachment_file(fname, charset, Filter)
                
    def send_email(self, subject, to_addrs, cc_addrs, content, subtype="plain", charset=None):
        '''Send the email to the receivers.
        @param subject:    the email's subject(title).
        @param to_addrs:   the receivers' addresses, it's a list looks like ["
 
[email protected]_server.com", "[email protected]_server.com"].
        @param cc_addrs:   the copy to receivers' addresses, has the same format as to_addrs.
        @param content:    the email message body, it can be plain text or HTML text, which depends on the parameter 'content_type'.
        @param subtype:    the content type, it can be "html" or "plain", default is "plain".
        @param charset:    the charset of message content, default is "None", use the same encoding as the initial function, which default is "utf-8".
        @return: if send successfully, return 'True', otherwise, return 'False'.
        '''
        charset = charset if charset is not None else self.encoding
        
        #Set the root information
        msg_root = MIMEMultipart("related")
        msg_root["Subject"] = subject
        msg_root["From"] = self.from_addr  # You can change it to any string
        msg_root["To"] = ",".join(to_addrs)
        msg_root["CC"] = ",".join(cc_addrs)
        msg_root["Date"] = formatdate(localtime=True)
        msg_root.preamble = "This is a multi-part message in MIME format."

        #Encapsulate the plain and HTML of the message body into an 'alternative' part,
        #so message agents can decide which they want to display.
        msg_alt = MIMEMultipart("alternative")

        #Set the message content
        msg_txt = MIMEText(content, subtype.lower(), charset)
        msg_alt.attach(msg_txt)

        #Add the alternative part to root part.
        msg_root.attach(msg_alt)

        #Add the attachment files
        for attach in self.attachments:
            msg_root.attach(attach)

        #Extend the copy to addresses to to_addrs
        to_addrs.extend(cc_addrs)

        #Send the email
        try:
            self.smtp.sendmail(self.from_addr, to_addrs, msg_root.as_string())
            self.print_verbose("Send email successfully.")
        except Exception as ex:
            print("Send email failed. Error info:%s"%(str(ex)))
            return False
        return True

    def close(self):
        '''Quit from the SMTP.
        '''
        self.smtp.quit()
        self.print_verbose("Logout SMTP server successfully.")
        
def test():
    smtp_server = "smtp.163.com"
    user = "yyy"
    password = "yyyxxx"
    from_addr = "
 
[email protected]"
    to_addrs = ["[email protected]"]
    cc_addrs = []
    subject = "Email sending test"
    content ='Dear Friends,<p/><a href="http://blog.csdn.net/thomashtq"> Welcome to my CSDN blog!</a> <p/>Thanks a lot!'
    attach_files=[r"D:\temp\sendemail\attach"]

    emailsender = EmailSender(smtp_server, verbose=True)
    emailsender.login(user, password)
    for attach in attach_files:
        emailsender.add_attachment(attach, "utf-8")
    emailsender.send_email(subject, to_addrs, cc_addrs, content, subtype="html", charset="utf-8")
    emailsender.close()
        
if __name__ == '__main__':
    test()