如何控制邮件的发送？

在python中，可以使用smtplib模块来发送邮件，并使用email模块来构造邮件内容。要控制邮件的发送，可以使用try-except语句及邮件发送的返回状态码来判断邮件是否发送成功，并在失败时进行相应的处理。

示例代码：

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

def send_email(send_from, send_to, subject, body, files=None):
    msg = MIMEMultipart()
    msg['From'] = send_from
    msg['To'] = ', '.join(send_to)
    msg['Subject'] = subject

    body_text = MIMEText(body, 'plain')
    msg.attach(body_text)

    if files:
        for f in files:
            with open(f, 'rb') as attach_file:
                attach_data = attach_file.read()
            attachment = MIMEApplication(attach_data, _subtype='pdf')
            attachment.add_header('Content-Disposition', 'attachment', filename=f)
            msg.attach(attachment)

    try:
        smtp_server = smtplib.SMTP('smtp.gmail.com', 587)
        smtp_server.ehlo()
        smtp_server.starttls()
        smtp_server.login('your_username', 'your_password')
        smtp_server.sendmail(send_from, send_to, msg.as_string())
        smtp_server.quit()
        print('Email sent successfully!')
    except smtplib.SMTPException as e:
        print('Email failed to send!')
        print(e)

此函数将使用带有文本正文和附件的MIMEMultipart实例构造电子邮件。如果邮件发送失败，则会打印错误消息。要发送电子邮件，您需要用自己的用户名和密码替换函数中的“your_username”和“your_password”。