help!

trying to send out presidents day sale to our customers using tools > send email... after I hit send meial it says:

Email Error: Could not instantiate mail function. Please check Admin->Configuration->Email Options->Email Transport.

So I went there and it is set up to PHP, send emails true

shouldn't it just send email?

do I need to set it up to SMTP instead and enter in my email send info? I would rather not have to do that, I think it should just have sent, please help, this is time critical.

thanks~