WordPress : How to make email field not required in comments

Recently I was thinking of ways to get more comments on my WordPress blog and one way to achieve that could be making the email field optional instead of required as some visitors might be unwilling to share their email just to drop a comment. It turns out this is not as easy as it sounds. It seems the WordPress has Name and Email tied up as you can only make either both optional or both required. This post will show you, how to make email an optional field while leaving the name field required.