If you receive something similar to this bounced email messege:
> 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. The following address(es) failed:
> Domain "yourdomainname" has exceeded the max defers and failures per hour
> (7/5 (10%)) allowed. Message discarded.
> ------ This is a copy of the message, including all the headers. ------
Then your account has triggered this due to sending out too many emails to addresses that either dont exist, or dont work.
All you need to do to avoid this is to ensure that your email addresses are up-to-date, and any bounced emails are removed from your system to prevent you repeatedly emailing the same faulty addresses.
This system is just another measure in place to protect you from potential server abusers or hacked websites from being abused.
We know its a real pain in the neck, but as so many refuse to keep their websites up-to-date, were having to put in place more measures to protect ourselves and others from ageing websites.