Python -使用smtplib发送给多个收件人

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

msg = MIMEMultipart()
msg['From'] = 'sender@example.com'
msg['To'] = ', '.join(['recipient1@example.com', 'recipient2@example.com'])
msg['Subject'] = '邮件主题'

body = '邮件正文内容'
msg.attach(MIMEText(body, 'plain'))

attachment = MIMEText(open('attachment.txt', 'rb').read(), 'base64', 'utf-8')
attachment['Content-Type'] = 'application/octet-stream'
attachment['Content-Disposition'] = 'attachment; filename="attachment.txt"'
msg.attach(attachment)

smtp_server = 'smtp.example.com'
smtp_port = 25
username = 'your_username'
password = 'your_password'

with smtplib.SMTP(smtp_server, smtp_port) as server:
    server.login(username, password)
    server.sendmail(msg['From'], msg['To'].split(', '), msg.as_string())