如何使用smtplib模块发送电子邮件及附件？

1. 导入smtplib模块和MIME模块

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

2. 设置发件人、收件人、主题和正文

sender = '发件人邮箱地址'
receiver = '收件人邮箱地址'
subject = '邮件主题'
body = '邮件正文'

3. 创建MIMEMultipart对象并设置发件人、收件人和主题

message = MIMEMultipart()
message['From'] = sender
message['To'] = receiver
message['Subject'] = subject

4. 创建MIMEText对象并设置正文

text = MIMEText(body)
message.attach(text)

5. 创建MIMEApplication对象并设置附件

with open('附件文件路径', 'rb') as f:
    attachment = MIMEApplication(f.read(), _subtype='pdf')
attachment.add_header('Content-Disposition', 'attachment', filename='附件文件名.pdf')
message.attach(attachment)

6. 连接SMTP服务器并登录，发送邮件

smtp_server = 'SMTP服务器地址'
smtp_port = 25 # SMTP服务器端口号
smtp_user = 'SMTP服务器用户名'
smtp_password = 'SMTP服务器密码'

smtp = smtplib.SMTP(smtp_server, smtp_port)
smtp.login(smtp_user, smtp_password)
smtp.sendmail(sender, receiver, message.as_string())
smtp.quit()

完整代码示例：

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

sender = '发件人邮箱地址'
receiver = '收件人邮箱地址'
subject = '邮件主题'
body = '邮件正文'

message = MIMEMultipart()
message['From'] = sender
message['To'] = receiver
message['Subject'] = subject

text = MIMEText(body)
message.attach(text)

with open('附件文件路径', 'rb') as f:
    attachment = MIMEApplication(f.read(), _subtype='pdf')
attachment.add_header('Content-Disposition', 'attachment', filename='附件文件名.pdf')
message.attach(attachment)

smtp_server = 'SMTP服务器地址'
smtp_port = 25 # SMTP服务器端口号
smtp_user = 'SMTP服务器用户名'
smtp_password = 'SMTP服务器密码'

smtp = smtplib.SMTP(smtp_server, smtp_port)
smtp.login(smtp_user, smtp_password)
smtp.sendmail(sender, receiver, message.as_string())
smtp.quit()