An ESET Server Security license key is a unique alphanumeric string (or a license file) that legally authenticates your installation of ESET’s server-grade antivirus and anti-malware software. It serves three primary functions:
ESET maintains a real-time blacklist of leaked or fraudulent license keys. Even if a key works for a few days, ESET’s update servers will eventually revoke it. Your server will then revert to “unprotected” mode, leaving you exposed. Eset Server Security License Key