import asyncio
import uvloop
from aiosmtpd.controller import Controller

# handler that just prints the message content
class PrintHandler:
    async def handle_DATA(self, server, session, envelope):
        print("Message from:", envelope.mail_from)
        print("Recipients:", envelope.rcpt_tos)
        print("Message data:")
        print(envelope.content.decode('utf8', errors='replace'))
        print("End of message")
        # Respond with a success code
        return '250 Message accepted for delivery'

# uvloop for better performance
asyncio.set_event_loop_policy(uvloop.EventLoopPolicy())

def run_server():
    # SMTP server controller, binding to localhost on port 25
    controller = Controller(PrintHandler(), hostname='127.0.0.1', port=25)
    controller.start()
    print("SMTP server running on port 25. Press Ctrl+C to stop.")
    try:
        # Run forever
        asyncio.get_event_loop().run_forever()
    except KeyboardInterrupt:
        pass
    finally:
        controller.stop()

if __name__ == '__main__':
    run_server()