Spam mail plz help

Hello,



I got a domain name and a server on the internet for my business i am getting a problem since two weeks ago my server has been infected with spam i am getting lot of spam mails .

It is getting the server to work very slow and also infecting pc.

What must be done to remove that infection on an online server?


I contacted my hosting administrator he said that he can't do nothing.

Please help me...