I don't know if any of y'all have done this recently, but our current website hosting service doesn't allow mass emails to be sent.
If you create a new post/topic, and open the +Attachments and other options, you'll notice an option called []Announce topic
DON'T USE IT. It sends an email to all #### registered members on the forum, resulting in a mass-email warning from our webhost. I don't know if this was the cause before, but we got warned about it 2 days ago, and I recently un-suspended our account with them via ticket.
Posted by Staff Member, on May 30, 2013, 17:25:24
Hello Jeremy,
Mass mail is strictly prohibited by our Terms Of Service: http://www.hosting24.com/tos.php
You can send no more than 19 emails per minute (using PHP). Additionally, You are allowed to send up to 100 emails/hour.