Unable to send e-mail using python

Question

I'm running Buster and use SMTP to send emails from the command line and it works just fine.

When I try to send emails using Python it fails miserably, I've tried various python examples from the net, eg

# Sending Email Alerts via Zoho
#
#
import smtplib

server = smtplib.SMTP_SSL('smtp.zoho.com',port=465) #server for sending the email

server.ehlo() # simple starting of the connection
server.login('test_email@zoho.com','pwd_12345') # login credentials and password

msg = """From:test_email@zoho.com
Subject: Test Email \n
To: recipient_email@gmail.com \n"""
# This is where the email content goes. It could be information about the error, time of day, where in the script, etc.

server.sendmail('test_email@zoho.com','recipient_email@gmail.com',msg) # this is where the email is sent to the recipient

server.quit() # exit the connection

.. but I unfortunately I always get the following error:

Traceback (most recent call last):
  File "/usr/lib/python3.7/smtplib.py", line 387, in getreply
    line = self.file.readline(_MAXLINE + 1)
  File "/usr/lib/python3.7/socket.py", line 589, in readinto
    return self._sock.recv_into(b)
ConnectionResetError: [Errno 104] Connection reset by peer

As a newbee any hint would be appreciated.

Thanks!

Answer 1

This could be a server/firewall configuration issue vs a programming issue. You need to verify that you can send an e-mail through the same server to the same destination via other means from the same device.

Answer 2

This issue has been solved!

My ISP uses SSL on port 465 and my command line email client MSMTP works just great using that.

As I was so desperate, so that I startet to play around and just use port 25 and "Bingo" the email notifications work now just fine, the funny part is that my ISP suggest to use port 465.