Multi tool use

SSL Error when connecting to a company Exchange Server

I try to send mails from out company exchange server via Python. My problem is, that I get a SSL error. I read a lot of pem-, cer-, crt-files, but I can not connect all these information to have success. I am sure, that if one can fix the issue in my little example script, one could fix the exchange script, too.

I read a lot about certificates and ca_bundles, but I don't know how to apply all of that to my issue.

Example-Script:

import requests
requests.get('https://mail.ourserver.loc')


Error:

C:Pythonpython.exe "PATHtoMYproject/testing.py"
Traceback (most recent call last):
File "C:Pythonlibsite-packagesurllib3contribpyopenssl.py", line 441, in wrap_socket
cnx.do_handshake()
File "C:Pythonlibsite-packagesOpenSSLSSL.py", line 1806, in do_handshake
self._raise_ssl_error(self._ssl, result)
File "C:Pythonlibsite-packagesOpenSSLSSL.py", line 1546, in _raise_ssl_error
_raise_current_error()
File "C:Pythonlibsite-packagesOpenSSL_util.py", line 54, in exception_from_error_queue
raise exception_type(errors)
OpenSSL.SSL.Error: [('SSL routines', 'tls_process_server_certificate', 'certificate verify failed')]

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
[.. a lot of text..]
ssl.SSLError: ("bad handshake: Error([('SSL routines', 'tls_process_server_certificate', 'certificate verify failed')],)",)

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
[.. a lot of text..]
urllib3.exceptions.MaxRetryError: HTTPSConnectionPool(host='mail.ourserver.loc', port=443): Max retries exceeded with url: / (Caused by SSLError(SSLError("bad handshake: Error([('SSL routines', 'tls_process_server_certificate', 'certificate verify failed')],)",),))


Exchange-Script:

from exchangelib import DELEGATE, Account, Credentials, Configuration, Message

import os

import urllib3
urllib3.disable_warnings()

creds = Credentials(username='EXGE-USR', password='secret')
config = Configuration(server='mail.ourserver.loc', credentials=creds)
account = Account(primary_smtp_address="user-name@ex-ample.com", autodiscover=False, config=config,
access_type=DELEGATE)

def send(email_receiver):
m = Message(
account=account,
subject='This is a test!',
body='Hallo',
to_recipients=[email_receiver])
m.send_and_save()

receiver = 'user-name@ex-ample.com'

send(email_receiver=receiver)

print('Finish')


Error:

C:Pythonpython.exe "PATHtoMYproject//exchange_main.py"
Traceback (most recent call last):
File "C:Pythonlibsite-packagesurllib3contribpyopenssl.py", line 441, in wrap_socket
cnx.do_handshake()
File "C:Pythonlibsite-packagesOpenSSLSSL.py", line 1806, in do_handshake
self._raise_ssl_error(self._ssl, result)
File "C:Pythonlibsite-packagesOpenSSLSSL.py", line 1546, in _raise_ssl_error
_raise_current_error()
File "C:Pythonlibsite-packagesOpenSSL_util.py", line 54, in exception_from_error_queue
raise exception_type(errors)
OpenSSL.SSL.Error: [('SSL routines', 'tls_process_server_certificate', 'certificate verify failed')]

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
[.. a lot of text..]
ssl.SSLError: ("bad handshake: Error([('SSL routines', 'tls_process_server_certificate', 'certificate verify failed')],)",)

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "C:Pythonlibsite-packagesrequestsadapters.py", line 440, in send
timeout=timeout
File "C:Pythonlibsite-packagesurllib3connectionpool.py", line 639, in urlopen
_stacktrace=sys.exc_info()[2])
File "C:Pythonlibsite-packagesurllib3utilretry.py", line 388, in increment
raise MaxRetryError(_pool, url, error or ResponseError(cause))
urllib3.exceptions.MaxRetryError: HTTPSConnectionPool(host='mail.ourserver.loc', port=443): Max retries exceeded with url: /EWS/Exchange.asmx (Caused by SSLError(SSLError("bad handshake: Error([('SSL routines', 'tls_process_server_certificate', 'certificate verify failed')],)",),))

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
[.. a lot of text..]
requests.exceptions.ConnectionError: HTTPSConnectionPool(host='mail.ourserver.loc', port=443): Max retries exceeded with url: /EWS/Exchange.asmx (Caused by SSLError(SSLError("bad handshake: Error([('SSL routines', 'tls_process_server_certificate', 'certificate verify failed')],)",),))

Process finished with exit code 1url: /EWS/Exchange.asmx (Caused by SSLError(SSLError("bad handshake: Error([('SSL routines', 'tls_process_server_certificate', 'certificate verify failed')],)",),))

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
[.. a lot of text..]
requests.exceptions.ConnectionError: HTTPSConnectionPool(host='mail.ourserver.loc', port=443): Max retries exceeded with url: /EWS/Exchange.asmx (Caused by SSLError(SSLError("bad handshake: Error([('SSL routines', 'tls_process_server_certificate', 'certificate verify failed')],)",),))

Process finished with exit code 1


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