FROM python:3.9-slim

WORKDIR /app

COPY requirements.txt requirements.txt
RUN pip install --no-cache-dir -r requirements.txt

COPY . .

# Hugging Face Spaces typically expects the application to run on port 7860
# and will route external traffic (HTTPS on port 443) to this internal port.
ENV PORT 7860
EXPOSE 7860

# Command to run your Flask app using Gunicorn
# Assumes your Flask app instance is named 'app' in 'email_sender_api.py'
CMD ["gunicorn", "--bind", "0.0.0.0:7860", "email_sender_api:app"]