While viewing exim_mainlog and seeing the following:
enforce_mail_permissions: Domain thedomain.com has exceeded the max defers and failures per hour (5/5 (100%)) allowed. Message discarded.
This occurs when an account is sending email to too many invalid recipient emails. This may be the result of:
- - bulk email sending
- - a script using that email address has been compromised
- - the email account itself is compromised
In such a case we recommend validating your recipient list, ensuring any PHP or java scripts you are using are up to date and secure, and/or changing the password of your email account and making sure you are using SSL/TLS for your email connections.
If you have a VPS or dedicated server, if necessary, you may increase the allowed defer emails via your web host manager tweak settings.
To reset an accounts defer block, remove the file at /var/cpanel/email_send_limits/max_deferfail_thedomain.com