Python之SMTP学习笔记方法详解

这是关于SMTP在python中的基本应用，一个学习python的爱好者的学习笔记。需要用到python sys、python smtplib、python socket等方法。

Python之SMTP学习笔记方法详解：
（1）首先，获得服务器的特性，如：允许发送的邮件大小；
（2）接着，查看服务器是否支持SSL和TLS安全传输；
（3）最后，查看在发送邮件之前是否需要认证。

#!/usr/bin/env python
#-*-coding = UTF-8-*-

import sys
import smtplib
import socket
from getpass import getpass

if len(sys.argv) < 4:
    print "[*]usage:%s server fromaddr toaddr " % sys.argv[0]
    sys.exit(1)

server = sys.argv[1]
fromaddr = sys.argv[2]
toaddr = sys.argv[3]

message = """
TO: %s
From: %s
Subject: Test Message from SMTP_mail.py

Hello ,This a simple SMTP_mail example.
""" % (','.join(toaddr),fromaddr)

#www.iplaypy.com

def get_size():
    """获得服务器允许发送邮件的大小"""
    try:
        s = smtplib.SMTP(server)     #连接到服务器

        code = s.ehlo()[0]      #返回服务器的特性

        usesesmtp = 1

        if not (200 <= code <=299):         #在200到299之间都是正确的返回值

            usesesntp = 0

            code = s.helo()[0]

            if not (200 <= code <=299):
                raise SMTPHeloError(code,resp)

        if usesesmtp and s.has_extn('size'):         #获得服务器允许发送邮件的大小
            print "Maxinum message size is ",s.esmtp_features['size']

            if len(message) > int(s.esmtp_features['size']):
                print "Message too large;aborting."
                sys.exit(2)

        s.sendmail(fromaddr,toaddr,message)

    except(socket.gaierror,socket.error,socket.herror,smtplib.SMTPException),e:
        print "***Your message may not have been sent!"
        print e
        sys.exit(1)

    else:
        print "***Message successful sent to %d recipient(s)" % len(toaddr)

def ssl_tls():
    """使用SSL安全套阶层和TLS安全传输层进行邮件传输，确保密码在传输中的安全"""
    try:
        s = smtplib.SMTP(server)     #连接到服务器

        code = s.ehlo()[0]      #返回服务器的特性

        usesesmtp = 1

        if not (200 <= code <=299):         #在200到299之间都是正确的返回值
            usesesntp = 0
            code = s.helo()[0]
            if not (200 <= code <=299):
                raise SMTPHeloError(code,resp)
        if usesesmtp and s.has_extn('starttls'):         #查看服务器是否支持TLS
            print "Negotiating TLS......"
            s.starttls()
            code = s.ehlo()[0]
            if not (200 <= code <=299):             #在支持TLS的服务器上是否连接回话成功
                print "Couldn't EHLO after STARTTLS."
                sys.exit(5)
            print "Using TLS connection."
        else:
            print "Server does not suport TLS; using normal connection."
        s.sendmail(fromaddr,toaddr,message)         #如果连接TLS成功则使用加密传输；若连接TLS出错则使用普通的传输
    except(socket.gaierror,socket.error,socket.herror,smtplib.SMTPException),e:
        print "***Your message may not have been sent!"
        print e
        sys.exit(1)
    else:
        print "***Message successful sent to %d recipient(s)" % len(toaddr)

def auth_login():
    """当发送邮件时，服务器需要验证，则输入用户名密码方可发送邮件"""
    sys.stdout.write("Enter username: ")
    username = sys.stdin.readline().strip()
    password = getpass("Enter password: ")
    try:
        s = smtplib.SMTP(server)     #连接到服务器
        code = s.ehlo()[0]      #返回服务器的特性
        usesesmtp = 1
        if not (200 <= code <=299):         #在200到299之间都是正确的返回值
            usesesntp = 0
            code = s.helo()[0]
            if not (200 <= code <=299):
                raise SMTPHeloError(code,resp)
        if usesesmtp and s.has_extn('auth'):         #查看服务器是否支持认证
            print "Using Authentication connect."
            try:
                s.login(username,password)
            except smtplib.SMTPException,e:
                print "Authentication failed:",e
                sys.exit(1)
        else:
            print "Server does not suport Authentication; using normal connect."
        s.sendmail(fromaddr,toaddr,message)         #如果支持认证则输入用户名密码进行认证；不支持则使用普通形式进行传输
    except(socket.gaierror,socket
2000
.error,socket.herror,smtplib.SMTPException),e:
        print "***Your message may not have been sent!"
        print e
        sys.exit(1)
    else:
        print "***Message successful sent to %d recipient(s)" % len(toaddr)

if __name__ == "__main__":
    get_size()
    ssl_tls()
    auth_login()

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