在Python如何使用SMTP发送邮件

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。

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。

#!/usr/bin/python
 
import smtplib
 
sender = 'from@fromdomain.com'
receivers = ['to@todomain.com']
 
message = """From: From PersonTo: To PersonSubject: 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"

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","小五义"):  
        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 PersonTo: To PersonMIME-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 
This is HTML message.This is headline."""
 
try:
   smtpObj = smtplib.SMTP('localhost')
   smtpObj.sendmail(sender, receivers, message)         
   print "Successfully sent email"
except SMTPException:
   print "Error: unable to send email"

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 PersonTo: To PersonSubject: 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"