exchangelib.errors.AutoDiscoverF

# exchangelib.errors.AutoDiscoverFailed

from exchangelib import DELEGATE, Account, Credentials, Message, Mailbox, HTMLBody,Configuration,NTLM
from exchangelib.protocol import BaseProtocol,NoVerifyHTTPAdapter
BaseProtocol.HTTP_ADAPTER_CLS = NoVerifyHTTPAdapter

def Email(to, subject, body):
    creds = Credentials(
        username='xxx.com\exadmin',
        password='Spinfo0'
    )
    config = Configuration(server='xxx.com', credentials=creds, auth_type=NTLM)
    account = Account(
        primary_smtp_address='xxx@xxx.com',
        credentials=creds,
        autodiscover=False,
        access_type=DELEGATE,
        config=config
    )
    m = Message(
        account=account,
        subject=subject,
        body=HTMLBody(body),
        to_recipients = [Mailbox(email_address=to)]
    )
    m.send()

Email("xxx@xxx.com", "abc", "def")