VPS High load and spamd

Hi,

My VPS cloud configuration as follows :

4 cores 3.1 GHZ
8 gb ram
CENTOS 6.8 x86_64 kvm
WHM 58.0 (build 31)

I am facing problem from last few days that my this vps load goes high on daily basis. 8/12 times in 24 hours. I am regular looking csf email of high alert and trying to findout what's a issue of highload.

Time: Sat Oct 1 08:08:03 2016 +0500
1 Min Load Avg: 50.62
5 Min Load Avg: 31.39
15 Min Load Avg: 15.70
Running/Total Processes: 4/407

Now I am noticing that spamd is taking too much load on vps and make it unstable

shekhamu xxx.com 49.0 spamd child

millacfo 17597 0.7 1.6 258948 129344 ? R 07:51 0:07 \_ spamd child
millacfo 21534 23.5 1.3 239516 109440 ? S 08:08 0:00 \_ spamd child
millacfo 21536 16.5 1.3 239444 109716 ? S 08:08 0:00 \_ spamd child

Need your guideline to fix issue

Thanks.