有没有办法在flask mail中命名附件中的pdf文件？

from flask import Flask
from flask_mail import Mail, Message
from email.mime.application import MIMEApplication

app = Flask(__name__)
app.config['MAIL_SERVER'] = 'smtp.example.com'
app.config['MAIL_PORT'] = 587
app.config['MAIL_USE_TLS'] = True
app.config['MAIL_USERNAME'] = 'your-email@example.com'
app.config['MAIL_PASSWORD'] = 'your-password'

mail = Mail(app)

@app.route('/')
def send_email():
    with app.open_resource('path/to/pdf/file.pdf') as pdf:
        msg = Message('Subject', sender='your-email@example.com', recipients=['recipient@example.com'])
        msg.attach(MIMEApplication(pdf.read(), 'pdf', name='custom_filename.pdf'))
        mail.send(msg)
    return 'Email sent'

if __name__ == '__main__':
    app.run()