Kerio Connect can block IP addresses suspicious of password guessing attacks (ten unsuccessful attempts in one minute). This article covers the process of protecting Kerio Connect against them.
- Go to Configuration > Security > Security Policy tab.
- Check the Block IP addresses suspicious of password guessing attacks option.
Note: IP address is blocked for individual services. If POP3 is blocked, an attacker can attempt to log in via IMAP.
- You can choose a group of trustworthy IP addresses.
- To block all services, check the option Block user accounts probably targeted by password guessing to lock the affected accounts.
- Click OK.
Confirmation: When an account is blocked, the user cannot log in.