如何多次编辑嵌入邮件？

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

# 创建邮件对象
msg = MIMEMultipart()

# 添加文本内容
text = "这是一封嵌入图片的邮件。"
msg.attach(MIMEText(text, 'plain'))

# 添加图片
with open('image.jpg', 'rb') as f:
    img = MIMEImage(f.read())
    img.add_header('Content-ID', '<image>')
    msg.attach(img)

# 设置邮件头
msg['From'] = 'sender@example.com'
msg['To'] = 'receiver@example.com'
msg['Subject'] = '嵌入图片的邮件'

# 发送邮件
server = smtplib.SMTP('smtp.example.com', 587)
server.starttls()
server.login('sender@example.com', 'password')
server.send_message(msg)
server.quit()