它可能会在你的信息中添加标签。在你把它传递给sendMail之前打印出消息。

我对发送电子邮件的包选项不满意，我决定制作并开源我自己的电子邮件发送器。它易于使用，并支持高级用例。

如何安装:

pip install redmail

用法:

from redmail import EmailSender
email = EmailSender(
    host="<SMTP HOST ADDRESS>",
    port=<PORT NUMBER>,
)

email.send(
    sender="me@example.com",
    receivers=["you@example.com"],
    subject="An example email",
    text="Hi, this is text body.",
    html="<h1>Hi,</h1><p>this is HTML body</p>"
)

如果您的服务器需要用户和密码，只需将user_name和密码传递给EmailSender。

我在send方法中包含了很多特性:

包含附件 将图像直接包含到HTML主体中 金贾的模板 漂亮的HTML表格开箱即用

文档: https://red-mail.readthedocs.io/en/latest/

源代码:https://github.com/Miksus/red-mail

在摆弄了很多例子之后，例如这里 这对我来说很管用:

import smtplib
from email.mime.text import MIMEText

# SMTP sendmail server mail relay
host = 'mail.server.com'
port = 587 # starttls not SSL 465 e.g gmail, port 25 blocked by most ISPs & AWS
sender_email = 'name@server.com'
recipient_email = 'name@domain.com'
password = 'YourSMTPServerAuthenticationPass'
subject = "Server - "
body = "Message from server"

def sendemail(host, port, sender_email, recipient_email, password, subject, body):
    try:
        p1 = f'<p><HR><BR>{recipient_email}<BR>'
        p2 = f'<h2><font color="green">{subject}</font></h2>'
        p3 = f'<p>{body}'
        p4 = f'<p>Kind Regards,<BR><BR>{sender_email}<BR><HR>'
        
        message = MIMEText((p1+p2+p3+p4), 'html')  
        # servers may not accept non RFC 5321 / RFC 5322 / compliant TXT & HTML typos

        message['From'] = f'Sender Name <{sender_email}>'
        message['To'] = f'Receiver Name <{recipient_email}>'
        message['Cc'] = f'Receiver2 Name <>'
        message['Subject'] = f'{subject}'
        msg = message.as_string()

        server = smtplib.SMTP(host, port)
        print("Connection Status: Connected")
        server.set_debuglevel(1)
        server.ehlo()
        server.starttls()
        server.ehlo()
        server.login(sender_email, password)
        print("Connection Status: Logged in")
        server.sendmail(sender_email, recipient_email, msg)
        print("Status: Email as HTML successfully sent")

    except Exception as e:
            print(e)
            print("Error: unable to send email")

# Run
sendemail(host, port, sender_email, recipient_email, password, subject, body)
print("Status: Exit")

我编写了一个简单的函数send_email()，用于使用smtplib和电子邮件包发送电子邮件(链接到我的文章)。它还使用dotenv包来加载发件人的电子邮件和密码(请不要在代码中保密!)我正在使用Gmail电子邮件服务。密码是应用程序密码(这里是谷歌文档如何生成应用程序密码)。

import os
import smtplib
from email.message import EmailMessage
from dotenv import load_dotenv
_ = load_dotenv()


def send_email(to, subject, message):
    try:
        email_address = os.environ.get("EMAIL_ADDRESS")
        email_password = os.environ.get("EMAIL_PASSWORD")

        if email_address is None or email_password is None:
            # no email address or password
            # something is not configured properly
            print("Did you set email address and password correctly?")
            return False

        # create email
        msg = EmailMessage()
        msg['Subject'] = subject
        msg['From'] = email_address
        msg['To'] = to
        msg.set_content(message)

        # send email
        with smtplib.SMTP_SSL('smtp.gmail.com', 465) as smtp:
            smtp.login(email_address, email_password)
            smtp.send_message(msg)
        return True
    except Exception as e:
        print("Problem during send email")
        print(str(e))
    return False

以上方法对于简单的电子邮件发送是可行的。如果您正在寻找更高级的功能，例如HTML内容或附件，当然可以手工编码，但我建议使用现有的包，例如yagmail。

Gmail每天限制500封邮件。对于每天发送许多电子邮件，请考虑事务性电子邮件服务提供商，如Amazon SES, MailGun, MailJet或SendGrid。

在缩进函数中的代码时(这是可以的)，还缩进了原始消息字符串的行。但是前导空白意味着标题行的折叠(连接)，如RFC 2822 - Internet Message Format的2.2.3和3.2.3节所述:

每个报头字段在逻辑上是由一行字符组成的 字段名、冒号和字段主体。为了方便 但是，为了处理每行998/78个字符的限制， 报头字段的字段主体部分可以分成多个 线表示;这叫做“折叠”。

在sendmail调用的函数形式中，所有行都以空白开始，因此是“展开的”(连接)，您正在尝试发送

From: monty@python.com    To: jon@mycompany.com    Subject: Hello!    This message was sent with Python's smtplib.

与我们的想法不同，smtplib将不再理解To:和Subject:头文件，因为这些名称只在一行的开头被识别。相反，smtplib将假设一个非常长的发送者电子邮件地址:

monty@python.com    To: jon@mycompany.com    Subject: Hello!    This message was sent with Python's smtplib.

这将不起作用，因此出现异常。

解决方案很简单:只保留原来的消息字符串。这可以通过一个函数来完成(正如Zeeshan建议的那样)，也可以直接在源代码中完成:

import smtplib

def sendMail(FROM,TO,SUBJECT,TEXT,SERVER):
    """this is some test documentation in the function"""
    message = """\
From: %s
To: %s
Subject: %s

%s
""" % (FROM, ", ".join(TO), SUBJECT, TEXT)
    # Send the mail
    server = smtplib.SMTP(SERVER)
    server.sendmail(FROM, TO, message)
    server.quit()

现在展开没有发生，你发送

From: monty@python.com
To: jon@mycompany.com
Subject: Hello!

This message was sent with Python's smtplib.

这就是您的旧代码所做的工作。

请注意，我还保留了标题和正文之间的空行，以适应RFC的第3.5节(这是必需的)，并根据Python风格指南PEP-0008(这是可选的)将include放在函数之外。

有压痕问题。下面的代码将工作:

import textwrap

def sendMail(FROM,TO,SUBJECT,TEXT,SERVER):
    import smtplib
    """this is some test documentation in the function"""
    message = textwrap.dedent("""\
        From: %s
        To: %s
        Subject: %s
        %s
        """ % (FROM, ", ".join(TO), SUBJECT, TEXT))
    # Send the mail
    server = smtplib.SMTP(SERVER)
    server.sendmail(FROM, TO, message)
    server.quit()