以下是使用Python编写的一个函数，用于向一个收件人发送基于模板的电子邮件。该函数中的常量（如sender_email，sender_password等）应该替换为您自己的SMTP服务器和电子邮件帐户详细信息。您还需要提供包含邮件内容的HTML文本模板文件。

import smtplib
from email.mime.text import MIMEText
from email.mime.multipart import MIMEMultipart
from email.mime.application import MIMEApplication
from jinja2 import Environment, FileSystemLoader


def send_templated_email(recipient_email, subject, template_file):
    sender_email = "sender@example.com"
    sender_password = "password"

    # load the HTML template
    file_loader = FileSystemLoader('templates')
    env = Environment(loader=file_loader)
    template = env.get_template(template_file)
    email_text = template.render()

    # create message object
    message = MIMEMultipart()
    message['From'] = sender_email
    message['To'] = recipient_email
    message['Subject'] = subject

    # attach HTML email body to message
    html_part = MIMEText(email_text, 'html')
    message.attach(html_part)

    # attach file to message
    with open("files/example.pdf", 'rb') as file:
        attach_file = MIMEApplication(file.read(), _subtype='pdf')
        attach_file.add_header('Content-Disposition', 'attachment', filename="example.pdf")
        message.attach(attach_file)

    # send email
    with smtplib.SMTP('smtp.gmail.com', 587) as smtp:
        smtp.starttls()
        smtp.login(sender_email, sender_password)
        smtp.send_message(message)

recipient_email = "recipient@example.com"
subject = "Test Email"
template_file = "template.html"

send_templated_email(recipient_email, subject, template_file)

在此示例中，我们使用Jinja2模板库来加载电子邮件正文的HTML文件（假设该文件位于名为“templates”的目录中）。模板可以从文件中加载，也可以在代码中作为字符串提供。最后，我们