使用本地服务器使用Django发送电子邮件成功。上传到heroku失败

heroku config:set EMAIL_HOST=smtp.gmail.com
heroku config:set EMAIL_PORT=587
heroku config:set EMAIL_USE_TLS=True
heroku config:set EMAIL_HOST_USER=your_email@gmail.com
heroku config:set EMAIL_HOST_PASSWORD=your_email_password

pip install sendgrid

EMAIL_BACKEND = 'sendgrid_backend.SendgridBackend'
SENDGRID_API_KEY = os.environ.get('SENDGRID_API_KEY')

heroku config:set SENDGRID_API_KEY=your_sendgrid_api_key

heroku logs --tail

from django.core.mail import send_mail
from django.http import HttpResponse

def send_email(request):
    send_mail(
        'Subject here',
        'Here is the message.',
        'from@example.com',
        ['to@example.com'],
        fail_silently=False,
    )
    return HttpResponse("Email sent!")

EMAIL_BACKEND = 'django.core.mail.backends.smtp.EmailBackend'
EMAIL_HOST = os.environ.get('EMAIL_HOST')
EMAIL_PORT = os.environ.get('EMAIL_PORT')
EMAIL_USE_TLS = os.environ.get('EMAIL_USE_TLS') == 'True'
EMAIL_HOST_USER = os.environ.get('EMAIL_HOST_USER')
EMAIL_HOST_PASSWORD = os.environ.get('EMAIL_HOST_PASSWORD')