AttributeError: 'NoneType' object has no attribute 'readuntil'

[cole]

AttributeError: 'NoneType' object has no attribute 'readuntil'

[skillian]

Though I'm not positive about this, my first suspicion is it might have to do with starting and stopping the loop between every call. I would recommend first moving all of your code that uses the smtp object into an async function and then passing the invocation of that function into loop.run_until_complete(my_async_function(smtp))

Hello, thanks for your quick response.

I have the same result with this code.

async def test(smtp):
    for i in range(30):
        msg = email.message_from_string(my_eml)
        await smtp.send_message(msg)
        sleep(0.5)

loop = asyncio.get_event_loop()
smtp = aiosmtplib.SMTP(hostname='gmail-smtp-in.l.google.com', port=25, loop=loop, use_tls=False)
loop.run_until_complete(smtp.connect())
loop.run_until_complete(smtp.starttls())

loop.run_until_complete(test(smtp))
smtp.close()

Have you an idea ?

[cole]

I can't reproduce error so far (testing with smtp.gmail.com). It seems like the server is dropping the connection without sending a response, but that should raise SMTPServerDisconnected.

One quick thing, for STARTTLS connections, typically the port is 587, not 25.

Yes, the server is dropping the connection without sending a response. I encountered this issue only with gmail. So, I will catch AttributeError exception. Thank for your help.

[cole]

Going to reopen this as a reminder to myself to add a test case for it.

[cole]

Can't reproduce this still. Closing.