New Multisite problem after latest upgrade

I manage a WP Multisite. I just upgraded to the latest version of wp-easy-smtp and email functionality has ceased. I can still however create a test email. I am using contact form 7 and that has stopped working. Worse though is that no emails are sent out when a new subsite is created.

I had had a problem with easy-smtp before, but at least the key emails were being sent out.

1. Should wp-easy-smtp work for Multisite?
2. If the answer is no, and the fact that it previously used to work partially was incidental, should I restore to the previous version of easy-smtp – or should I look for another plugin?

Regards.

https://wordpress.org/plugins/easy-wp-smtp/