使用MIMEMultipart()在Python中发送带有文本文件附件的邮件

在Python中使用MIMEMultipart()发送带有文本文件附件的邮件可以按照以下步骤进行：

1. 首先，导入必要的库：smtplib用于发送邮件、email.mime.multipart和email.mime.text用于构建邮件内容。

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

2. 创建一个MIMEMultipart对象，它将作为我们要发送的邮件的容器。

msg = MIMEMultipart()

3. 设置邮件的主题、发件人、收件人和正文。

msg['Subject'] = 'Email with Text File Attachment'
msg['From'] = 'sender@example.com'
msg['To'] = 'recipient@example.com'
body = 'Please find the attached text file.'
msg.attach(MIMEText(body, 'plain'))

4. 读取并附加要发送的文本文件。

filename = 'text_file.txt'
attachment = open(filename, 'rb')
part = MIMEText(attachment.read(), 'plain')
part.add_header('Content-Disposition', 'attachment', filename=filename)
msg.attach(part)
attachment.close()

5. 设置邮件服务器的信息，并使用SMTP协议发送邮件。

smtp_server = 'smtp.example.com'
username = 'sender@example.com'
password = 'password'

server = smtplib.SMTP(smtp_server, port=587)
server.starttls()
server.login(username, password)
server.sendmail(msg['From'], msg['To'], msg.as_string())
server.quit()

完整的代码示例如下：

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

msg = MIMEMultipart()

msg['Subject'] = 'Email with Text File Attachment'
msg['From'] = 'sender@example.com'
msg['To'] = 'recipient@example.com'
body = 'Please find the attached text file.'
msg.attach(MIMEText(body, 'plain'))

filename = 'text_file.txt'
attachment = open(filename, 'rb')
part = MIMEText(attachment.read(), 'plain')
part.add_header('Content-Disposition', 'attachment', filename=filename)
msg.attach(part)
attachment.close()

smtp_server = 'smtp.example.com'
username = 'sender@example.com'
password = 'password'

server = smtplib.SMTP(smtp_server, port=587)
server.starttls()
server.login(username, password)
server.sendmail(msg['From'], msg['To'], msg.as_string())
server.quit()

请确保替换示例中的实际邮箱地址、SMTP服务器和认证信息，以适应您的具体需求。