我正在尝试使用python发送电子邮件（Gmail），但出现以下错误。

Traceback (most recent call last):  
File "emailSend.py", line 14, in <module>  
server.login(username,password)  
File "/usr/lib/python2.5/smtplib.py", line 554, in login  
raise SMTPException("SMTP AUTH extension not supported by server.")  
smtplib.SMTPException: SMTP AUTH extension not supported by server.

Python脚本如下。

import smtplib
fromaddr = 'user_me@gmail.com'
toaddrs  = 'user_you@gmail.com'
msg = 'Why,Oh why!'
username = 'user_me@gmail.com'
password = 'pwd'
server = smtplib.SMTP('smtp.gmail.com:587')
server.starttls()
server.login(username,password)
server.sendmail(fromaddr, toaddrs, msg)
server.quit()

您需要先说一下EHLO才能直接进入STARTTLS：

server = smtplib.SMTP('smtp.gmail.com:587')
server.ehlo()
server.starttls()

此外，你应该真正创造From:，To:以及Subject:邮件标题，一个空行，并使用从邮件正文中分离出来CRLF作为EOL标志。

例如

msg = "\r\n".join([
  "From: user_me@gmail.com",
  "To: user_you@gmail.com",
  "Subject: Just a message",
  "",
  "Why, oh why"
  ])

def send_email(user, pwd, recipient, subject, body):
    import smtplib

    FROM = user
    TO = recipient if isinstance(recipient, list) else [recipient]
    SUBJECT = subject
    TEXT = body

    # Prepare actual message
    message = """From: %s\nTo: %s\nSubject: %s\n\n%s
    """ % (FROM, ", ".join(TO), SUBJECT, TEXT)
    try:
        server = smtplib.SMTP("smtp.gmail.com", 587)
        server.ehlo()
        server.starttls()
        server.login(user, pwd)
        server.sendmail(FROM, TO, message)
        server.close()
        print 'successfully sent the mail'
    except:
        print "failed to send mail"

如果要使用端口465，则必须创建一个SMTP_SSL对象：

# SMTP_SSL Example
server_ssl = smtplib.SMTP_SSL("smtp.gmail.com", 465)
server_ssl.ehlo() # optional, called by login()
server_ssl.login(gmail_user, gmail_pwd)  
# ssl server doesn't support or need tls, so don't call server_ssl.starttls() 
server_ssl.sendmail(FROM, TO, message)
#server_ssl.quit()
server_ssl.close()
print 'successfully sent the mail'

我遇到了类似的问题，偶然发现了这个问题。我收到SMTP身份验证错误，但我的用户名/密码正确。这是修复它的原因。我读到这个：

https://support.google.com/accounts/answer/6010255

简而言之，Google不允许您通过smtplib登录，因为它已将这种登录标记为“安全性较低”，因此您要做的就是在登录google帐户时转到此链接，并允许访问：

https://www.google.com/settings/security/lesssecureapps

设置好之后（请参见下面的屏幕截图），它应该可以工作。

现在可以登录：

smtpserver = smtplib.SMTP("smtp.gmail.com", 587)
smtpserver.ehlo()
smtpserver.starttls()
smtpserver.ehlo()
smtpserver.login('me@gmail.com', 'me_pass')

更改后的响应：

(235, '2.7.0 Accepted')

事先回应：

smtplib.SMTPAuthenticationError: (535, '5.7.8 Username and Password not accepted. Learn more at\n5.7.8 http://support.google.com/mail/bin/answer.py?answer=14257 g66sm2224117qgf.37 - gsmtp')

还是行不通？如果仍然收到SMTPAuthenticationError，但现在的代码为534，则因为位置未知。点击此链接：

https://accounts.google.com/DisplayUnlockCaptcha

单击继续，这将给您10分钟的时间注册新应用。因此，现在就进行另一次登录尝试，它应该可以工作。

更新：这似乎无法立即生效，您可能会在smptlib中遇到此错误一段时间：

235 == 'Authentication successful'
503 == 'Error: already authenticated'

该消息显示使用浏览器登录：

SMTPAuthenticationError: (534, '5.7.9 Please log in with your web browser and then try again. Learn more at\n5.7.9 https://support.google.com/mail/bin/answer.py?answer=78754 qo11sm4014232igb.17 - gsmtp')

启用“ lesssecureapps”后，去喝杯咖啡，回来，然后再次尝试“ DisplayUnlockCaptcha”链接。根据用户的经验，更改可能最多需要一个小时才能生效。然后再次尝试登录过程。

你对OOP失望吗？

#!/usr/bin/env python


import smtplib

class Gmail(object):
    def __init__(self, email, password):
        self.email = email
        self.password = password
        self.server = 'smtp.gmail.com'
        self.port = 587
        session = smtplib.SMTP(self.server, self.port)        
        session.ehlo()
        session.starttls()
        session.ehlo
        session.login(self.email, self.password)
        self.session = session

    def send_message(self, subject, body):
        ''' This must be removed '''
        headers = [
            "From: " + self.email,
            "Subject: " + subject,
            "To: " + self.email,
            "MIME-Version: 1.0",
           "Content-Type: text/html"]
        headers = "\r\n".join(headers)
        self.session.sendmail(
            self.email,
            self.email,
            headers + "\r\n\r\n" + body)


gm = Gmail('Your Email', 'Password')

gm.send_message('Subject', 'Message')

这个作品

创建Gmail APP密码！

创建之后，请创建一个名为 sendgmail.py

然后添加以下代码：

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
# =============================================================================
# Created By  : Jeromie Kirchoff
# Created Date: Mon Aug 02 17:46:00 PDT 2018
# =============================================================================
# Imports
# =============================================================================
import smtplib

# =============================================================================
# SET EMAIL LOGIN REQUIREMENTS
# =============================================================================
gmail_user = 'THEFROM@gmail.com'
gmail_app_password = 'YOUR-GOOGLE-APPLICATION-PASSWORD!!!!'

# =============================================================================
# SET THE INFO ABOUT THE SAID EMAIL
# =============================================================================
sent_from = gmail_user
sent_to = ['THE-TO@gmail.com', 'THE-TO@gmail.com']
sent_subject = "Where are all my Robot Women at?"
sent_body = ("Hey, what's up? friend!\n\n"
             "I hope you have been well!\n"
             "\n"
             "Cheers,\n"
             "Jay\n")

email_text = """\
From: %s
To: %s
Subject: %s

%s
""" % (sent_from, ", ".join(sent_to), sent_subject, sent_body)

# =============================================================================
# SEND EMAIL OR DIE TRYING!!!
# Details: http://www.samlogic.net/articles/smtp-commands-reference.htm
# =============================================================================

try:
    server = smtplib.SMTP_SSL('smtp.gmail.com', 465)
    server.ehlo()
    server.login(gmail_user, gmail_app_password)
    server.sendmail(sent_from, sent_to, email_text)
    server.close()

    print('Email sent!')
except Exception as exception:
    print("Error: %s!\n\n" % exception)

因此，如果成功，将看到如下图像：

我通过向自己发送电子邮件和向自己发送电子邮件进行了测试。

注意：我的帐户启用了两步验证。应用密码与此配合使用！（对于gmail smtp设置，您必须转到https://support.google.com/accounts/answer/185833?hl=zh_CN并执行以下步骤）

此设置不适用于启用了两步验证的帐户。此类帐户需要特定于应用程序的密码，以降低安全性。

您可以在这里找到它：http : //jayrambhia.com/blog/send-emails-using-python

smtp_host = 'smtp.gmail.com'
smtp_port = 587
server = smtplib.SMTP()
server.connect(smtp_host,smtp_port)
server.ehlo()
server.starttls()
server.login(user,passw)
fromaddr = raw_input('Send mail by the name of: ')
tolist = raw_input('To: ').split()
sub = raw_input('Subject: ')

msg = email.MIMEMultipart.MIMEMultipart()
msg['From'] = fromaddr
msg['To'] = email.Utils.COMMASPACE.join(tolist)
msg['Subject'] = sub  
msg.attach(MIMEText(raw_input('Body: ')))
msg.attach(MIMEText('\nsent via python', 'plain'))
server.sendmail(user,tolist,msg.as_string())

没有直接关系，但仍然值得指出的是，我的程序包试图使发送Gmail消息真正快速而轻松。它还尝试维护错误列表，并尝试立即指向解决方案。

实际上，只需要此代码即可完成您编写的操作：

import yagmail
yag = yagmail.SMTP('user_me@gmail.com')
yag.send('user_you@gmail.com', 'Why,Oh why!')

或一个班轮：

yagmail.SMTP('user_me@gmail.com').send('user_you@gmail.com', 'Why,Oh why!')

对于软件包/安装，请查看git或pip，它们可用于Python 2和3。

这是一个Gmail API示例。尽管更复杂，但这是我发现的唯一一种在2019年有效的方法。该示例摘自并修改自：

https://developers.google.com/gmail/api/guides/sending

您需要通过其网站使用Google API接口创建一个项目。接下来，您需要为您的应用启用GMAIL API。创建凭据，然后下载这些凭据，将其另存为凭据.json。

import pickle
import os.path
from googleapiclient.discovery import build
from google_auth_oauthlib.flow import InstalledAppFlow
from google.auth.transport.requests import Request

from email.mime.text import MIMEText
import base64

#pip install --upgrade google-api-python-client google-auth-httplib2 google-auth-oauthlib

# If modifying these scopes, delete the file token.pickle.
SCOPES = ['https://www.googleapis.com/auth/gmail.readonly', 'https://www.googleapis.com/auth/gmail.send']

def create_message(sender, to, subject, msg):
    message = MIMEText(msg)
    message['to'] = to
    message['from'] = sender
    message['subject'] = subject

    # Base 64 encode
    b64_bytes = base64.urlsafe_b64encode(message.as_bytes())
    b64_string = b64_bytes.decode()
    return {'raw': b64_string}
    #return {'raw': base64.urlsafe_b64encode(message.as_string())}

def send_message(service, user_id, message):
    #try:
    message = (service.users().messages().send(userId=user_id, body=message).execute())
    print( 'Message Id: %s' % message['id'] )
    return message
    #except errors.HttpError, error:print( 'An error occurred: %s' % error )

def main():
    """Shows basic usage of the Gmail API.
    Lists the user's Gmail labels.
    """
    creds = None
    # The file token.pickle stores the user's access and refresh tokens, and is
    # created automatically when the authorization flow completes for the first
    # time.
    if os.path.exists('token.pickle'):
        with open('token.pickle', 'rb') as token:
            creds = pickle.load(token)
    # If there are no (valid) credentials available, let the user log in.
    if not creds or not creds.valid:
        if creds and creds.expired and creds.refresh_token:
            creds.refresh(Request())
        else:
            flow = InstalledAppFlow.from_client_secrets_file(
                'credentials.json', SCOPES)
            creds = flow.run_local_server(port=0)
        # Save the credentials for the next run
        with open('token.pickle', 'wb') as token:
            pickle.dump(creds, token)

    service = build('gmail', 'v1', credentials=creds)

    # Example read operation
    results = service.users().labels().list(userId='me').execute()
    labels = results.get('labels', [])

    if not labels:
        print('No labels found.')
    else:
        print('Labels:')
    for label in labels:
        print(label['name'])

    # Example write
    msg = create_message("from@gmail.com", "to@gmail.com", "Subject", "Msg")
    send_message( service, 'me', msg)

if __name__ == '__main__':
    main()

现在有一个gmail API，可让您通过REST发送电子邮件，阅读电子邮件和创建草稿。与SMTP调用不同，它是非阻塞的，这对于基于线程的Web服务器在请求线程中发送电子邮件（例如python Web服务器）可能是一件好事。该API也非常强大。

• 当然，应该将电子邮件传递到非Web服务器队列，但是有选项很高兴。

如果您对域具有Google Apps管理员权限，那么设置起来最容易，因为这样您就可以授予客户一揽子许可。否则，您必须摆弄OAuth身份验证和权限。

这是一个证明它的要点：

https://gist.github.com/timrichardson/1154e29174926e462b7a

@David的好答案，这是针对不带通用try-except的Python 3的：

def send_email(user, password, recipient, subject, body):

    gmail_user = user
    gmail_pwd = password
    FROM = user
    TO = recipient if type(recipient) is list else [recipient]
    SUBJECT = subject
    TEXT = body

    # Prepare actual message
    message = """From: %s\nTo: %s\nSubject: %s\n\n%s
    """ % (FROM, ", ".join(TO), SUBJECT, TEXT)

    server = smtplib.SMTP("smtp.gmail.com", 587)
    server.ehlo()
    server.starttls()
    server.login(gmail_user, gmail_pwd)
    server.sendmail(FROM, TO, message)
    server.close()

在您的gmail帐户上启用安全性较低的应用并使用（Python> = 3.6）：

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

gmailUser = 'XXXXX@gmail.com'
gmailPassword = 'XXXXX'
recipient = 'XXXXX@gmail.com'

message = f"""
Type your message here...
"""

msg = MIMEMultipart()
msg['From'] = f'"Your Name" <{gmailUser}>'
msg['To'] = recipient
msg['Subject'] = "Subject here..."
msg.attach(MIMEText(message))

try:
    mailServer = smtplib.SMTP('smtp.gmail.com', 587)
    mailServer.ehlo()
    mailServer.starttls()
    mailServer.ehlo()
    mailServer.login(gmailUser, gmailPassword)
    mailServer.sendmail(gmailUser, recipient, msg.as_string())
    mailServer.close()
    print ('Email sent!')
except:
    print ('Something went wrong...')

好像是老问题了smtplib。在python2.7一切正常。

更新：是的，server.ehlo()也可以提供帮助。

    import smtplib

    fromadd='from@gmail.com'
    toadd='send@gmail.com'

    msg='''hi,how r u'''
    username='abc@gmail.com'
    passwd='password'

    try:
        server = smtplib.SMTP('smtp.gmail.com:587')
        server.ehlo()
        server.starttls()
        server.login(username,passwd)

        server.sendmail(fromadd,toadd,msg)
        print("Mail Send Successfully")
        server.quit()

   except:
        print("Error:unable to send mail")

   NOTE:https://www.google.com/settings/security/lesssecureapps that                                                         should be enabled

import smtplib
server = smtplib.SMTP('smtp.gmail.com', 587)
server.ehlo()
server.starttls()
server.login("fromaddress", "password")
msg = "HI!"
server.sendmail("fromaddress", "receiveraddress", msg)
server.quit()