Office 365 SMTP自定义域名发邮件认证失败求助

我需要使用托管在Office 365中的自定义域名邮箱support@example.com向用户发送邮件，当前Django邮件后端配置如下：

# Email settings
EMAIL_BACKEND = "django.core.mail.backends.smtp.EmailBackend"
EMAIL_HOST = "smtp.office365.com"
EMAIL_PORT = 587
EMAIL_USE_TLS = True
EMAIL_HOST_USER = "support@example.com"
EMAIL_HOST_PASSWORD = "App_password"

执行发送时遇到的具体错误：

Authentication unsuccessful, the request did not meet the criteria to be authenticated successfully. Contact your administrator.

我已验证登录凭据的正确性，同时尝试了587和25端口，问题仍未解决。

对比成功配置：
使用个人Outlook邮箱personal@outlook.com搭配smtp-mail.outlook.com可正常发送邮件，配置如下：

EMAIL_BACKEND = "django.core.mail.backends.smtp.EmailBackend"
EMAIL_HOST = "smtp-mail.outlook.com"
EMAIL_PORT = 587
EMAIL_USE_TLS = True
EMAIL_HOST_USER = "personal@outlook.com"
EMAIL_HOST_PASSWORD = "App_password"

我确认问题与邮件发送函数无关，以下是函数代码：

def send_email_verification(user):
    site_url = "https://www.example.com"
    print("Trying to send email")

    if user.is_active:
        return
    else:
        print("sending email")
        confirmation_token = default_token_generator.make_token(user)  # unique token
        activation_link = f"{site_url}/users/api/users/activate/{user.id}/{confirmation_token}"   # activation link to be sent in email

        subject = "Verify your Email address"
        from_email = settings.EMAIL_HOST_USER
        to_email = user.email


        # Load the email template and render it with the activation link
        html_content = render_to_string('email_verification.html', {'activation_link' : activation_link})
        text_content = strip_tags(html_content)         # This strips the html, so people will have the text.


        # Create the email, message and send it.
        msg = EmailMultiAlternatives(subject, text_content, from_email, [to_email])
        msg.attach_alternative(html_content, "text/html")

        try:
            msg.send()
            print(f"Email successfully sent to {user.email}")
            print(f"confirmation toke = {confirmation_token}")
        except Exception as e:
            print(f"an error  has occured while sending email : {e}")

恳请有类似经验的人士提供建议、见解或解决方案，感谢支持！

内容的提问来源于stack exchange，提问作者Nawaraj