rejected Status Messages
When there is an issue with an email account, the sender may receive a "Recipient address rejected" status message also known as a "bounce." The following are some common "Recipient address rejected" status messages and their typical meaning:
The recipient has exceeded their storage quota.
The recipient does not exist.
The recipient has been suspended for violating one or more service agreement terms.
The recipient is an ad-supported (free) Web Mail user as resources have been temporarily diverted.
The sender that is trying to reach the recipient is sending their message from a network that is known to be the origin of excess spam.
Other errors can be found here.