The IP was already used for trialing on...

Issue

Plesk web host server is sending following emails multiple times a day:

From: This email address is being protected from spambots. You need JavaScript enabled to view it.
Subject: Cron <root@localhost> /usr/bin/kcarectl --auto-update --gradual-rollout=auto
Content: The IP 76.15.48.179 was already used for trialing on 2018-07-05

Resolution

The issue was caused by expired trial of KernelCare Plesk extension. If you need functionality of this extension, buy a commercial license. Otherwise remove it from Plesk:

• Login to Plesk admin console
• Navigate to Extensions > My Extensions > KernelCare > Remove

August 2018
Plesk Web Host Edition 17.8
Linux CentOS 7.5