Exchange Server DNS

Hi I am new to excahnge and i have a question.When using SBS 2003 with exchange 2003
it asks for dns servers during the “Connect to Internet and Email Wizard” what dns address do i put there? Do i have to use the dns from my internet connection provider or can i use the dns from my website’s dns. my server is setup as corp.businessname.com and this name is used in the mx record where my website businessname.com is located. there is also an
“A” record for the name there.