I think you must check the reason why the client is being blocked. Since the latest post you said that brute force monitor (BFM) did this, that means, client might have entered wrong password in some applications that being monitored by BFM (example PHPmyadmin, email program). What you could temporary do is to remove that IP from the list, you can do this in GUI through Directadmin Brute Force Monitor icon. There is a button to remove the IP from the blocked list.
I suspect that the client might have putting a wrong or an old invalid email authentication and have not changed that info and he is being blocked frequently by BFM. I had experienced this before. You might want to read this if this help:
https://forum.directadmin.com/threads/how-to-exclude-specific-bruteforce-notification.58640/ . The post does not provide solution (just to ignore blocked notification) but the the real solution is to ask him to remove the invalid authentication to avoid being blocked..
You can also enable this feature to whitelist an IP address by creating this file and put IP address per-line there
Code:
nano /usr/local/directadmin/data/admin/ip_whitelist
then enable this in directadmin.conf like this
Code:
/usr/local/directadmin/directadmin set ip_whitelist /usr/local/directadmin/data/admin/ip_whitelist restart
Or, you can disable the brute force monitor completely (not recommend):
/usr/local/directadmin/directadmin set bruteforce 0 restart