Max Defers Failures
If you’re receiving an error same to as “Domain example.com has exceeded the max defers and failures per hour (5/5(100%)) allowed” in an email reclaim, it means outgoing email from your domain has triggered a rule in the server that may stop to any extent further email from going out of the server. This happens once a site domain account sends out emails that either fail or get delayed. If the amount of failures or defers are greater than the server limit, no additional mails ar allowed.
This error comes from an hourly observation system, wherever any blocked domains are allowed to send email again at the top of every hour.