Howto add new WordPress post by email

Update(06-25-2014): WordPress post by email is now deprecated, please reefer to the link below.

Alternatives: You can achieve the same goal using WordPress Official plugin JetPack

WordPress have a feature to add new post by email. That is the email body will become your post content. You can get that option on admin/setting/writing. Give the details of your secret mail.

Now the big Q?