The following SQL query should update all of your users to disable the "Receive System Emails" setting:
UPDATE #__users SET sendEmail = 0;
More importantly though, I'd figure out why all those users are set that way. Otherwise, I'm assuming new users will have the wrong setting, and this problem will continue with them.
I'm guessing you're also not using JFBConnect, our
Social Networking integration extension for Joomla
, but if you are, let us know if you're having any issues with that. Our primary support role is for our extensions. If you need general Joomla support, we'd recommend the
Joomla Forums
.
Thanks,
Alex