Confirm the source and jail
Record the verified user's public IP, the affected service, time and error. A Plesk panel access restriction, a network firewall and a Fail2Ban jail can all deny access; identify the layer before unblocking. Shared office networks and reverse proxies require particular care because many users may appear under one address.
In Plesk's IP address banning tools, inspect the banned address and the jail responsible. Review relevant authentication logs using a restricted channel. A real compromised client can generate failed attempts alongside a legitimate user's request.
Restore access narrowly
After verifying the user and activity, use the supported Plesk unban action for the specific address and jail. Avoid disabling all jails or broadly trusting a network just to solve one login problem. If an application repeatedly uses an old password, update its credentials before unbanning or it may be blocked again.
Review thresholds, retry intervals and trusted proxy configuration against the actual traffic pattern. Never trust arbitrary forwarded IP headers from untrusted clients.
Test and follow up
Confirm the affected user can complete the intended login and that repeated invalid attempts are still controlled. Record the reason, action and any time-limited exception. If the events suggest account compromise, preserve evidence and follow the security response process instead of simply allowing the source.
Further reading
Read the official documentation. For help applying these checks, explore Clouvenix services.