Python使用SMTP发送邮件

SMTP(Simple Mail Transfer Protocol)即简单邮件传输协议,它是一组用于由源地址到目的地址传送邮件的规则,由它来控制信件的中转方式。

python的smtplib提供了一种很方便的途径发送电子邮件。它对smtp协议进行了简单的封装。

Python创建 SMTP 对象语法如下:

import smtplib

smtpObj = smtplib.SMTP( [host [, port [, local_hostname]]] )

参数说明:

  • host: SMTP 服务器主机。 你可以指定主机的ip地址或者域名如:w3cschool.cc,这个是可选参数。
  • port: 如果你提供了 host 参数, 你需要指定 SMTP 服务使用的端口号,一般情况下SMTP端口号为25。
  • local_hostname: 如果SMTP在你的本机上,你只需要指定服务器地址为 localhost 即可。

Python SMTP对象使用sendmail方法发送邮件,语法如下:

SMTP.sendmail(from_addr, to_addrs, msg[, mail_options, rcpt_options]

参数说明:

  • from_addr: 邮件发送者地址。
  • to_addrs: 字符串列表,邮件发送地址。
  • msg: 发送消息

这里要注意一下第三个参数,msg是字符串,表示邮件。我们知道邮件一般由标题,发信人,收件人,邮件内容,附件等构成,发送邮件的时候,要注意msg的格式。这个格式就是smtp协议中定义的格式。

实例

以下是一个使用Python发送邮件简单的实例:

#!/usr/bin/python

import smtplib

sender = 'from@fromdomain.com'
receivers = ['to@todomain.com']

message = """From: From Person <from@fromdomain.com>
To: To Person <to@todomain.com>
Subject: SMTP e-mail test

This is a test e-mail message.
"""

try:
   smtpObj = smtplib.SMTP('localhost')
   smtpObj.sendmail(sender, receivers, message)         
   print "Successfully sent email"
except SMTPException:
   print "Error: unable to send email"

使用Python发送HTML格式的邮件

Python发送HTML格式的邮件与发送纯文本消息的邮件不同之处就是将MIMEText中_subtype设置为html。具体代码如下:

import smtplib  
from email.mime.text import MIMEText  
mailto_list=["YYY@YYY.com"] 
mail_host="smtp.XXX.com"  #设置服务器
mail_user="XXX"    #用户名
mail_pass="XXXX"   #口令 
mail_postfix="XXX.com"  #发件箱的后缀
  
def send_mail(to_list,sub,content):  #to_list:收件人;sub:主题;content:邮件内容
    me="hello"+"<"+mail_user+"@"+mail_postfix+">"   #这里的hello可以任意设置,收到信后,将按照设置显示
    msg = MIMEText(content,_subtype='html',_charset='gb2312')    #创建一个实例,这里设置为html格式邮件
    msg['Subject'] = sub    #设置主题
    msg['From'] = me  
    msg['To'] = ";".join(to_list)  
    try:  
        s = smtplib.SMTP()  
        s.connect(mail_host)  #连接smtp服务器
        s.login(mail_user,mail_pass)  #登陆服务器
        s.sendmail(me, to_list, msg.as_string())  #发送邮件
        s.close()  
        return True  
    except Exception, e:  
        print str(e)  
        return False  
if __name__ == '__main__':  
    if send_mail(mailto_list,"hello","<a href='http://www.cnblogs.com/xiaowuyi'>小五义</a>"):  
        print "发送成功"  
    else:  
        print "发送失败"  

或者你也可以在消息体中指定Content-type为text/html,如下实例:

#!/usr/bin/python

import smtplib

message = """From: From Person <from@fromdomain.com>
To: To Person <to@todomain.com>
MIME-Version: 1.0
Content-type: text/html
Subject: SMTP HTML e-mail test

This is an e-mail message to be sent in HTML format

<b>This is HTML message.</b>
<h1>This is headline.</h1>
"""

try:
   smtpObj = smtplib.SMTP('localhost')
   smtpObj.sendmail(sender, receivers, message)         
   print "Successfully sent email"
except SMTPException:
   print "Error: unable to send email"

Python发送带附件的邮件

发送带附件的邮件,首先要创建MIMEMultipart()实例,然后构造附件,如果有多个附件,可依次构造,最后利用smtplib.smtp发送。

from email.mime.text import MIMEText
from email.mime.multipart import MIMEMultipart
import smtplib

#创建一个带附件的实例
msg = MIMEMultipart()

#构造附件1
att1 = MIMEText(open('d:\\123.rar', 'rb').read(), 'base64', 'gb2312')
att1["Content-Type"] = 'application/octet-stream'
att1["Content-Disposition"] = 'attachment; filename="123.doc"'#这里的filename可以任意写,写什么名字,邮件中显示什么名字
msg.attach(att1)

#构造附件2
att2 = MIMEText(open('d:\\123.txt', 'rb').read(), 'base64', 'gb2312')
att2["Content-Type"] = 'application/octet-stream'
att2["Content-Disposition"] = 'attachment; filename="123.txt"'
msg.attach(att2)

#加邮件头
msg['to'] = 'YYY@YYY.com'
msg['from'] = 'XXX@XXX.com'
msg['subject'] = 'hello world'
#发送邮件
try:
    server = smtplib.SMTP()
    server.connect('smtp.XXX.com')
    server.login('XXX','XXXXX')#XXX为用户名,XXXXX为密码
    server.sendmail(msg['from'], msg['to'],msg.as_string())
    server.quit()
    print '发送成功'
except Exception, e:  
    print str(e) 

以下实例指定了Content-type header 为 multipart/mixed,并发送/tmp/test.txt 文本文件:

#!/usr/bin/python

import smtplib
import base64

filename = "/tmp/test.txt"

# 读取文件内容并使用 base64 编码
fo = open(filename, "rb")
filecontent = fo.read()
encodedcontent = base64.b64encode(filecontent)  # base64

sender = 'webmaster@tutorialpoint.com'
reciever = 'amrood.admin@gmail.com'

marker = "AUNIQUEMARKER"

body ="""
This is a test email to send an attachement.
"""
# 定义头部信息
part1 = """From: From Person <me@fromdomain.net>
To: To Person <amrood.admin@gmail.com>
Subject: Sending Attachement
MIME-Version: 1.0
Content-Type: multipart/mixed; boundary=%s
--%s
""" % (marker, marker)

# 定义消息动作
part2 = """Content-Type: text/plain
Content-Transfer-Encoding:8bit

%s
--%s
""" % (body,marker)

# 定义附近部分
part3 = """Content-Type: multipart/mixed; name=\"%s\"
Content-Transfer-Encoding:base64
Content-Disposition: attachment; filename=%s

%s
--%s--
""" %(filename, filename, encodedcontent, marker)
message = part1 + part2 + part3

try:
   smtpObj = smtplib.SMTP('localhost')
   smtpObj.sendmail(sender, reciever, message)
   print "Successfully sent email"
except Exception:
   print "Error: unable to send email"