Due to the high volume of mail we receive, we have implemented a rate limit policy. Please be advised that using your account for sending spam will result in termination. In order to prevent abuse of PHP scripts, we have decided to disallow any mail sent without SMTP authentication. When sending emails via SMTP, please ensure that you do not exceed 120 emails per hour and no more than 5 emails in a 2-minute timeframe. Please be aware that we closely monitor our mail usage and review any emails that are stuck in the queue (unable to send) to determine if they contain spam. In most cases, emails get stuck in the queue due to errors from the receiving server or message delivery issues.