I'm using Jomsocial and jevents. Both of these applications are email intensive. Sending emails to add Friends, Join Groups, Create Events, event invitations, event payments, etc.
Does your Sendy product make Sendy the default email engine for Joomla? That way i can use the bounce and spam features of Sendy to manage these emails. Thanks.
No. Sendy is only for sending newsletters and auto-responders. It's not meant for transactional mail, which is what you describe.
I'd recommend looking into using Mandrill or something similar which are meant as mail relays for transactional emails both to take the load off your server and to let you track response history. Mandrill is what we use on this site and what you should get the notification update to this thread from.
I hope that helps,