Connection unexpectedly closed: [Errno 104] Connection reset by peer about chasquid HOT 3 CLOSED

Thanks for the bug report and for all the details! Some questions:

1. What do the chasquid logs say? That should help determine what the server is seeing.
2. What is the error from the Python code?
3. Can you re-run the smtp-check? The ip address of your server seems to have changed, so maybe it was a matter of DNS propagation?

from chasquid.

   smtpObj = smtplib.SMTP() 
   smtpObj.connect(mail_host, 465)

You seem to confuse two ways to use TLS with client-server SMTP (aka Submission).

1. Implicit TLS
   The connection is initially protected using TLS. This is what is used on the standard port 465.

2. STARTTLS
   The connection is initially established in plaintext but after ESMTP negotiation TLS is activated using STARTTLS command. This is what is used on the standard port 587.

For 1, use smtplib.SMTP_SSL(). For 2, use smtplib.SMTP() and then call smtplib.starttls().

Your error is caused by an attempt to use plaintext SMTP on port with Implicit TLS. That is, server expects client to initiate TLS but it instead sends SMTP EHLO.

Note: Just using above is not sufficient to make connection secure (sigh Python sigh). https://stackoverflow.com/questions/33857698/sending-email-from-python-using-starttls

from chasquid.

@hyahm, I'm going to close this for now as it's been 3 months and we need more information to understand better what's going on, as explained in the last two comments.

If you have more information, please reopen so we can follow up. Thanks!

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