Hello there,
Thanks for contacting us.
From the above queries, we assume you want to have a common email sending system for both site A & site B.
We would like to inform you that we are currently working on a feature in which you can install the Email Subscribers plugin on the main site and allow subscriptions from other sites.
For example, you have a site A which is your main website where the Email Subscribers plugin is installed. Then you can create a subscription form and add it to both site A and site B.
When someone subscribes through the form either on site A or site B, he/she will automatically get added to your site A’s subscriber list. You can then send post notifications emails to both of your site A and site B subscribers from there. We will let you know when this feature goes out.
Note: In the free version, you can send post notification emails whenever a post is published. In the pro version, we have an option to combine multiple post notifications into one email and send them on daily, weekly, or monthly basis.
I hope I was able to clear your queries. Let us know if you have any further queries.
Thank you.