Mageplaza
Use SMTP no authorization for Office 365 in Magento 2
First of all you need to install Mageplaza Extension , you can find it here
https://github.com/mageplaza/magento-2-smtp
after you create O365 SMTP connector that you may use as smtp server to allow sending out emails as group
you need to override this class
vendor\mageplaza\module-smtp\Model\Config\Source\Authentication.php
change value of None from '' into 'smtp'.
then go to the configuration and choose None and click on Save
that's it :)