If you receive an email that says:
This message was created automatically by mail delivery software. A message that you sent could not be delivered to one or more of its recipients. This is a permanent error.
youremail@address
Domain 'yourdomain' has exceeded the max defers and failures per hour (10/10 (100%)) allowed. Message discarded.
Reporting-MTA: dns; server.chillidoghosting.com
Action: failed
Final-Recipient: your@recipients
Status: 5.0.0
From: Orders youremail@address
Subject: Re: Subject
Date:
To: your@recipient
cPanel temporarily blocks a domain from sending email if the number of failed or deferred messages the domain has sent in the last 60 minutes is high. It will stop sending out all email from that domain so your server doesn't get blocked permanently by other email servers (worldwide).
It resets every 60 min so it's temporary. Spammers send out mass emails to a lot of emails, many of which are invalid while humans usually don't. You should be OK going forward if you've removed those invalid emails from your address book.
