That email indicates that you have installed a kernel that either has no Kernelcare patches applied to it as yet, or that is unsupported by Kernelcare.
Assuming it is a supported kernel, you will receive an email every 4 hours (the default frequency that Kernelcare checks for available kernel patches) until Cloudlinux has issued a patch for that particular kernel, and your system has downloaded it and installed it.
If it is an unsupported kernel, you will receive that email message indefinitely, and should investigate whether you are running a compatible kernel to work with Kernelcare.
I always get the same messages after re-basing my kernels to the latest issued. In theory, one shouldn't need to update the kernel at all if you are using Kernelcare, but I choose to re-base once a year (because I am old and grumpy and set in my ways !)