I am Getting lot of spam mails in my Inbox

You can blacklist the domain from which the spam mails are receiving by,

Login to the cpanel of your domain by yourdomainname/cpanel

1. Click on spam assassin option under mail,
2. Enable spam Assassin
3. Enable Spam Box,
4. Click on Configure SpamAssassin
5. To block all the mails from a particular domain , give *@domainname.com [ex. *@gmail.com ] in Blacklist_from option.
6. Click on Save.